Pluto 1
Author's First Image WITH Pluto!!!
Pluto entering...
JPL's
Fire and Ice Page
Hubble Space
Telescope images of Pluto
IAU Press Release on Pluto
Nine
Planets Page (SEDS)
Views
of the Solar System by Calvin Hamilton
Lots
of Pluto Web Sites
Pluto Express
Hubble Images Pluto
Pluto Homepage
Gemini Infrared
Views of Pluto and Charon
NASA-funded researchers have discovered the most distant object orbiting Earth's sun. The object is a mysterious planet-like body three times farther from Earth than Pluto.
"The sun appears so small from that distance that you could completely block it out with the head of a pin," said Dr. Mike Brown, California Institute of Technology (Caltech), Pasadena, Calif., associate professor of planetary astronomy and leader of the research team. The object, called Sedna for the Inuit goddess of the ocean, is 13 billion kilometers (8 billion miles) away, in the farthest reaches of the solar system.
This is likely the first detection of the long-hypothesized "Oort cloud," a faraway repository of small icy bodies that supplies the comets that streak by Earth. Other notable features of Sedna include its size and reddish color. After Mars, it is the second reddest object in the solar system. It is estimated Sedna is approximately three- fourths the size of Pluto. Sedna is likely the largest object found in the solar system since Pluto was discovered in 1930.
Brown, along with Drs. Chad Trujillo of the Gemini Observatory, Hawaii and David Rabinowitz of Yale University, New Haven, Conn., found the planet-like object, or planetoid, on Nov. 14, 2003. The researchers used the 48-inch Samuel Oschin Telescope at Caltech's Palomar Observatory near San Diego. Within days, telescopes in Chile, Spain, Arizona and Hawaii observed the object. NASA's new Spitzer Space Telescope also looked for it.
Sedna is extremely far from the sun, in the coldest know region of our solar system, where temperatures never rise above minus 240 degrees Celsius (minus 400 degrees Fahrenheit). The planetoid is usually even colder, because it approaches the sun only briefly during its 10,500- year solar orbit. At its most distant, Sedna is 130 billion kilometers (84 billion miles) from the sun, which is 900 times Earth's solar distance.
Scientists used the fact that even the Spitzer telescope was unable to detect the heat of the extremely distant, cold object to determine it must be less than 1,700 kilometers (about 1,000 miles) in diameter, which is smaller than Pluto. By combining available data, Brown estimated Sedna's size at about halfway between Pluto and Quaoar, the planetoid discovered by the same team in 2002.
The elliptical orbit of Sedna is unlike anything previously seen by astronomers. However, it resembles that of objects predicted to lie in the hypothetical Oort cloud. The cloud is thought to explain the existence of certain comets. It is believed to surround the sun and extend outward halfway to the star closest to the sun. But Sedna is 10 times closer than the predicted distance of the Oort cloud. Brown said this "inner Oort cloud" may have been formed by gravity from a rogue star near the sun in the solar system's early days.
"The star would have been close enough to be brighter than the full moon, and it would have been visible in the daytime sky for 20,000 years," Brown explained. Worse, it would have dislodged comets farther out in the Oort cloud, leading to an intense comet shower that could have wiped out some or all forms of life that existed on Earth at the time.
Rabinowitz said there is indirect evidence that Sedna may have a moon. The researchers hope to check this possibility with NASA's Hubble Space Telescope. Trujillo has begun to examine the object's surface with one of the world's largest optical/infrared telescopes, the 8-meter (26- foot) Frederick C. Gillett Gemini Telescope on Mauna Kea, Hawaii. "We still don't understand what is on the surface of this body. It is nothing like what we would have predicted or what we can explain," he said.
Sedna will become closer and brighter over the next 72 years, before it begins its 10,500-year trip to the far reaches of the solar system. "The last time Sedna was this close to the sun, Earth was just coming out of the last ice age. The next time it comes back, the world might again be a completely different place," Brown said.
NASA's Jet Propulsion Laboratory, Pasadena, Calif, manages the Spitzer Space Telescope. For more information about the research and images on the Internet, visit:The planetoid, currently known only as 2004 DW, could be even larger than Quaoar--the current record holder in the area known as the Kuiper Belt--and is some 4.4 billion miles from Earth.
According to the discoverers, Caltech associate professor of planetary astronomy Mike Brown and his colleagues Chad Trujillo (now at the Gemini North observatory in Hawaii), and David Rabinowitz of Yale University, the planetoid was found as part of the same search program that discovered Quaoar in late 2002. The astronomers use the 48-inch Samuel Oschin Telescope at Palomar Observatory and the recently installed QUEST CCD camera built by a consortium including Yale and the University of Indiana, to systematically study different regions of the sky each night.
Unlike Quaoar, the new planetoid hasn't yet been pinpointed on old photographic plates or other images. Because its orbit is therefore not well understood yet, it cannot be given an official name.
"So far we only have a one-day orbit," said Brown, explaining that the data covers only a tiny fraction of the orbit the object follows in its more than 300-year trip around the sun. "From that we know only how far away it is and how its orbit is tilted relative to the planets."
The tilt that Brown has measured is an astonishingly large 20 degrees, larger even than that of Pluto, which has an orbital inclination of 17 degrees and is an anomaly among the otherwise planar planets.
The size of 2004 DW is not yet certain; Brown estimates a size of about 1,400 kilometers, based on a comparison of the planetoid's luminosity with that of Quaoar. Because the distance of the object can already be calculated, its luminosity should be a good indicator of its size relative to Quaoar, provided the two objects have the same albedo, or reflectivity.
Quaoar is known to have an albedo of about 10 percent, which is slightly higher than the reflectivity of our own moon. Thus, if the new object is similar, the 1,400-kilometer estimate should hold. If its albedo is lower, then it could actually be somewhat larger; or if higher, smaller.
According to Brown, scientists know little about the albedos of objects this large this far away, so the true size is quite uncertain. Researchers could best make size measurements with the Hubble Space Telescope or the newer Spitzer Space Telescope.
The continued discovery of massive planetoids on the outer fringe of the solar system is further evidence that objects even farther and even larger are lurking out there. "It's now only a matter of time before something is going to be discovered out there that will change our entire view of the outer solar system," Brown says.
The team is working hard to uncover new information about the planetoid, which they will release as it becomes available, Brown adds. Other telescopes will also be used to better characterize the planetoid's features.
Pluto 1 |
Author's First Image WITH Pluto!!! |
Pluto entering... |
|
|
|
STScI Press Release N.: STScI-PR02-17, October 9, 2002
NASA's Hubble Space Telescope has measured the largest object in the solar system ever seen since the discovery of Pluto 72 years ago. Approximately half the size of Pluto, the icy world is called "Quaoar" (pronounced kwa-whar). Quaoar is about 4 billion miles away, more than a billion miles farther than Pluto. Like Pluto, Quaoar dwells in the Kuiper belt, an icy belt of comet-like bodies extending 7 billion miles beyond Neptune's orbit.
Michael Brown and Chadwick Trujillo of Caltech are reported the findings at the 34th annual meeting of the Division for Planetary Sciences of the American Astronomical Society in Birmingham, Ala.
Earlier this year, Trujillo and Brown used the Palomar Oschin Schmidt telescope to discover Quaoar as an 18.5-magnitude object creeping across the summer constellation Ophiuchus (it's less than 1/10,000th the brightness of the faintest star seen by the human eye). Brown had to do follow-up observations using Hubble's new Advanced Camera for Surveys on July 5 and August 1, 2002, to measure the object's true angular size of 40 milliarcseconds, corresponding to a diameter of about 800 miles (1300 kilometers). Only Hubble has the sharpness needed to actually resolve the disk of the distant world, leading to the first-ever direct measurement of the true size of a Kuiper belt object (KBO).
See http://oposite.stsci.edu/pubinfo/pr/2002/17
MIT and Williams College Press Release, October 9, 2002
CAMBRIDGE, Mass., and WILLIAMSTOWN, Mass.--Pluto is undergoing global warming, as evidenced by a three-fold increase in the planet's atmospheric pressure during the past 14 years--a team of astronomers from Massachusetts Institute of Technology (MIT), Williams College, the University of Hawaii, Lowell Observatory, and Cornell University announced in a press conference at today's meeting of the Division of Planetary Sciences of the American Astronomical Society in Birmingham, AL.
The team, led by James Elliot, professor of planetary astronomy and director of MIT's Wallace Observatory, made this finding by watching the dimming of a star when Pluto passed in front of it last August 20. The team carried out observations using eight telescopes at Mauna Kea Observatory and Haleakala in Hawaii, Lick Observatory and Palomar Observatory in California, and Lowell Observatory in Arizona. Data were successfully recorded at all sites. An earlier attempt to observe an occultation of Pluto on July 20 in Chile with observations only from two sites with small telescopes, as the giant telescopes involved lost out to bad weather or from being in the wrong location.
The Williams College team included Jay Pasachoff, Bryce Babcock, Steven Souza, and undergraduate David Ticehurst. For the August event, they used a Williams College electronic camera mounted to a University of Hawaii telescope on Mauna Kea to make studies of the occultation in visible light. They found a dimming lasting 7 minutes, about one-third of their 2400 data frames, with fine detail that remains under study and reanalysis. Their visible-light data are being compared with infrared data obtained by the team at other telescopes.
Elliot said the new results have surprised the observers, who as recently as July thought that Pluto's atmosphere may be cooling. "From the July data we know that Pluto's atmosphere had changed since 1988, but the August data allowed us to probe much more deeply into Pluto's atmosphere and have given us a more accurate picture of the changes that have occurred," he said.
Pasachoff, an astronomy professor at Williams College, said that Pluto's global warming was "likely not connected with that of the Earth. The major way they could be connected is if the warming was caused by a large increase in sunlight. But the solar constant--the amount received of sunlight each second--is carefully monitored by spacecraft, and we know the Sun's output is much too steady to be changing the temperature of Pluto."
Pluto's elliptical orbit is much more out of round than that of the other planets, and its rotational pole is tipped by a large angle relative to its orbit. Both factors could contribute to drastic seasonal changes. .Pluto's atmospheric temperature varies between around minus 235 and minus 170 degrees Centigrade, depending on the altitude above the surface. The main gas in Pluto's atmosphere is nitrogen, and Pluto has nitrogen ice on its surface that can evaporate into the atmosphere when it gets warmer, causing an increase in surface pressure. If the observed increase in the atmosphere also applies to the surface pressure--which is likely the case--this means that the average surface temperature of the nitrogen ice on Pluto has increased slightly less than 2 degrees Centigrade over the past 14 years.
Marc Buie, an astronomer at Lowell Observatory, has been measuring the amount of sunlight reflected by Pluto and says that "the pressure increase can be explained if the average amount of sunlight reflected by the surface has decreased, which means that more heat is absorbed from the sun. This could be the reason that the pressure has been pumped up."
David Tholen, an astronomer at the University of Hawaii who measured the size of Pluto in the late 1980s using a series of occultations and eclipses involving Pluto's satellite, noted that even though Pluto was closest to the Sun in 1989, a warming trend 13 years later shouldn't be unexpected. "It takes time for materials to warm up and cool off, which is why the hottest part of the day on Earth is usually around 2 or 3 p.m. rather than local noon, when sunlight is the most intense," Tholen said. Because Pluto's year is equal to about 250 Earth years, 13 years after Pluto's closest approach to the Sun is like 1:15 p.m. on Earth. "This warming trend on Pluto could easily last for another 13 years," Tholen estimated.
Researchers study faraway objects through occultationsQeclipse-like events in which a body passes in front of a star (Pluto in this case), blocking the star's light from view. By recording the dimming of the starlight over time, astronomers can calculate the density, pressure and temperature of Pluto's atmosphere. Observing two or more occultations at different times provides researchers with information about changes in the planet's atmosphere. The structure and temperature of Pluto's atmosphere was first determined during an occultation in 1988.
Pluto's brief pass in front of a different star on July 19 led researchers to believe that a drastic atmospheric change was under way, but it was unclear whether the atmosphere was warming up or cooling down.
In August 2002, a team from Williams College, the University of Hawaii, and MIT, in an expedition arranged by Elliot, Tholen, and Pasachoff to the University of Hawaii's telescope in Mauna Kea, successfully observed the occultation of a faint star by Pluto.
The data resulting from this occultation, when Pluto passed in front of a star known as "P131.1," led to the current results. "This is the first time that an occultation has allowed us to probe so deeply into the atmosphere with a large telescope, which gives a high spatial resolution of a few kilometers," Elliot said.
A 1997 occultation of a star by Triton (Neptune's largest moon) revealed that its surface had warmed since the Voyager spacecraft first explored it in 1989. Pasachoff and Babcock, along with then Williams student Tim McConnochie, participated in those observations. On Triton, "Voyager saw dark material rising up as much as 12 km above the surface, indicating some kind of eruptive activity," Elliot said. "There could be more massive activity on Pluto, since the changes observed in Pluto's atmosphere are much more severe. The change observed on Triton was subtle. Pluto's changes are not subtle."
Pluto and Triton are presently about the same distance from the sun, and each has a predominantly nitrogen atmosphere (with a surface pressure 100,000 times less than that on Earth), so one might expect similar processes to be occurring on these two bodies.
NASA is still deciding whether to send a spacecraft to Pluto, the only planet not yet observed at close range. The Pluto-Kuiper Belt mission in the New Horizons Program, if approved, would be launched in 2006 and would reach Pluto 10 years later, seeks to answer questions about the surfaces, atmospheres, interiors and space environments of the solar system's outermost objects, including Pluto and its moon, Charon.
Researchers are looking forward to observing additional Pluto occultations in the years before the Pluto-Kuiper mission flies by Pluto. Of particular interest is the prospect of using SOFIA, a 2.5-meter airborne telescope being built by NASA in collaboration with German astronomers, for Pluto-occultation events when it begins operating in 2004. Edward Dunham, who leads the occultation effort at Lowell Observatory, is also leading a team that is building HIPO, a SOFIA instrument designed specifically to observe occultations. The combination of HIPO and SOFIA will provide very high quality data on a much more frequent basis than is possible using ground-based telescopes alone.
"This is a very complex process, and we just don't know what is causing these effects" on Pluto's surface, Elliot said. "That's why you need to send a mission."
This work is funded by Research Corporation, the National Science Foundation, and NASA's Planetary Astronomy Program.
A press release from Lowell Observatory last summer (based on results
of the July occultation) is at the website:
http://www.lowell.edu/Press/20020815.html
A map of Pluto's shadow crossing the Earth for the August occultation:
http://occult.mit.edu/research/occultations/Candidates/Predictions/P131.1.html
Images and further discussion of the observations for the August
occultation are on the Williams College site:
http://www.williams.edu/Astronomy/mkpluto.html
TEAM PARTICIPANTS IN THE PLANNING, PREDICTION, AND OBSERVATION, AND STUDY OF THE 2002 AUGUST PLUTO OCCULTATION
AEOS Telescope, Haleakala: Lewis Roberts, John Africano, Doyle Hall, Paul Kerwin, Mark Skinner
Cornell University: Stephen Eikenberry, Dae-Sik Moon, Philip Nicholson
Joint Astronomy Centre: Sandy K. Leggett
Lowell Observatory: Edward Dunham, Amanda Bosh (also Boston University), Marc Buie, Catherine Olkin, Brian Taylor
MIT: James Elliot, Katie Carbonari, Kelly Clancy, Erica McEvoy, Alison Klesman, Susan Kern, David Osip, Michael Person, Shen Qu
University of Hawaii: David Tholen and John Rayner
US Naval Observatory (Flagstaff): Stephen Levine and Ronald Stone
Williams College: Jay M. Pasachoff, Steven P. Souza, Bruce A. Babcock, David R. Ticehurst
Jay M. Pasachoff 7/30/2002
Pluto, 6 billion kilometers away, is so small that it occults (hides) a star very rarely. In fact, the only previous time it had been known to do so was 1988, when a team led by MIT professor James Elliot had detected its atmosphere. Note that if Pluto or another body had no atmosphere, the star would wink out abruptly (aside, technically, from optical effects), but that an atmosphere can bend and distort the starlight so that it fades gradually. In that way, the 1988 occultation gave a lot of information about Pluto's atmosphere. The light curve (the graph of brightness versus time) showed an abrupt change at a certain height above Pluto's surface, and two competing models have been invoked to explain it: a temperature inversion or the presence of dust.
Elliot and his colleagues have worked since then to find another Pluto occultation to observe. Pluto is only 0.1 arcsec across, about 1/10 the smallest size normally seen by the best telescopes and 1/5 the smallest size resolvable by Hubble. Stars are so far away that their light is parallel, and they project Pluto's shadow full size on the Earth. Thus the shadow of Pluto on the Earth from a star is about 2300 km across. Even the best astrometry (position measuring) gives an uncertainty of 1000 km or so a few days in advance of the occultation, though the Elliot group monitors the positions of Pluto and the star as time progresses, continually improving their predictions.
They predicted that on July 19/20, a Pluto occultation would be observable from Chile. They assembled a team of scientists to observe it and got observing time on some of the world's largest and newest telescopes, including 8-m Gemini South and the two 6.5-m Magellan telescopes in Chile. Three teams with portable 35-cm telescopes but with fast-readout CCD's, capable of observing twice a second to give time resolution unlike ordinary CCD's, were also participating: one team from MIT, one team from Lowell Observatory, and my own team from Williams College. We were to be deployed to the sides of the large telescopes, perhaps 200 km north or south, to increase the chance that somebody would see the event. A similar consortium, headed by Bruno Sicardy of the Observatory of Paris at Meudon, had the 8-m Very Large Telescope and other fixed and mobile telescopes.
As the time approached, the prediction shifted considerably north, making it look that sites from mid-Peru north through Central America would see the occultation, and some of our teams prepared to shift north. My own team was going to Aruba, given some connections with a customs agent there from the 1998 solar eclipse expedition and the weather that was predicted to be better than that in Central America. Customs and shipping problems prevented us finally from getting there, though we tried. But by that time, we were in contact with scientists at four large telescopes at the major observatories in the Canary Islands, which were in the same part of the track as Aruba, and helped arrange the use of two of them, including Pablo Perez at the 4.2 m William Herschel telescope on La Palma and a Belgian group of astronomers (Katrien Uytterhoeven, Roeland Van Malderen, Geert Davignon) at the 1.2 m telescope on La Palma. Mark Kidger was already using the 1.5 and 0.8 m telescopes on Tenerife for both optical and infrared observations.
In the event, the track shifted back south. The Canary Island telescopes got good data, but showed a steady light curve, with no occultation. One member of the French team saw the occultation from near Arica at Chile's northern boundary, though he used the drift technique across the CCD to give time resolution, making it relatively difficult to get accurate photometry. The Elliot-related team of Marc Buie of the Lowell Observatory and Oscar Saa of the Cerro Tololo Inter-American Observatory had complete success in observing the occultation from a site near Iquique, Chile, a couple of hundred kilometers south of the Peruvian border. They saw an occultation lasting about 104 s, with a dimming of about a factor of 2 at maximum. It will take some time for the results to be studied and to percolate into new models of Pluto's atmosphere.
Pluto is moving into a part of the sky with more stars, and a couple of occultations may be visible each year. The next one is scheduled for August 20, 2002, and as of this writing is to go over the major telescopes at Mauna Kea, Hawaii, several of which are to be devoted to the occultation. My own team from Williams College is taking our CCD to the 2.2-m telescope of the University of Hawaii there.
Johns Hopkins University Applied Physics Laboratory press release February 22, 2002
New Horizons mission planners have developed a new strategy that could trim nearly a year off their original schedule to send a spacecraft to the solar system's outermost planet.
Now in preliminary development for NASA, New Horizons would be the first mission to explore Pluto and its moon, Charon, as well as the ancient Kuiper Belt of rocky, icy objects beyond the planets. If approved and funded later this year, New Horizons would launch in January 2006, swing around Jupiter for scientific studies and a gravity boost in 2007, and reach Pluto as early as 2015.
"As we continued to study the mission, and optimized our launch window, we realized that we could get the spacecraft to Pluto sooner," says New Horizons Mission Director Robert W. Farquhar, of The Johns Hopkins University Applied Physics Laboratory in Laurel, Md., which manages the mission and will build and operate the spacecraft. "In our best estimates we can cover the 3 billion miles from Earth to Pluto faster than we once thought, while keeping all the mission's goals intact."
New Horizons project leaders say a faster trip benefits the mission in many ways.
"This a great opportunity to improve our scientific return while reducing mission risks and costs," says New Horizons Principal Investigator S. Alan Stern, of the Southwest Research Institute in Boulder, Colo. "We'll get a better look at Pluto itself, since more of the surface will be sunlit and the atmosphere will be another year away from freezing onto the planet's surface. We'll have more fuel for the journey into the Kuiper Belt after exploring Pluto-Charon, and the shorter cruise time reduces some of the costs associated with flight operations."
New Horizons will characterize the global geology and geomorphology of Pluto and Charon, map their surface compositions and temperatures, and study Pluto's complex atmosphere in detail. The spacecraft will then visit up to three Kuiper Belt objects beyond Pluto.
The Administration released its proposed FY2003 budget for NASA today. This is the first budget developed by the Bush Administration and the new NASA Administrator, Mr. Sean O'Keefe. The Division for Planetary Sciences (DPS) of the American Astronomical Society commends the support this budget provides for planetary exploration, which includes a new initiative for nuclear power and propulsion, and a second new initiative for a New Frontier line of competitively procured planetary space flight missions. Funding has been increased in real dollars for Research and Analysis programs, which provide a fundamental knowledge base allowing for the design of focused, efficient missions.
The Administration gave high ratings to the Discovery program of low-cost planetary missions and as a result has introduced a new line of moderately priced missions modeled on the Discovery program. The New Frontier missions would be about twice the cost of Discovery missions. The budget proposal would provide for about one Frontier mission every three years, bringing a new level of flight opportunity to the science community with competitively procured missions of higher capability.
The DPS is concerned about the cancellation of the outer planets program, which included the New Horizons mission to Pluto and the Europa Orbiter. The cost-capped New Horizons mission was recently selected after an open competition in which scientists and their industry partners spent millions of dollars and months of time in good faith response to a NASA call for proposals. This precedent discourages community participation in NASA's efforts to produce cost-effective missions through competition. It should not be repeated. Whether New Horizons may be resurrected in the New Frontier program will depend on its ultimate prioritization in the Planetary Decadal Survey.
The surprise in this budget is the proposal to revive development of nuclear technology for in-space propulsion and power. Development of this technology was terminated in the 1970s and planetary exploration has been limited ever since to long, complex flight missions using conventional propulsion and to spacecraft barely capable of powering a single light bulb. Nuclear propulsion will increase accessibility of Solar System objects and decrease the flight time for some missions. On-board nuclear power will provide a power-rich environment for science investigations at the planets and increase the lifetime of these systems to years instead of a few weeks or months.
The planetary Research and Analysis program was given a 3% increase above inflation, and a new program was funded at $10M to develop planetary instruments for biological investigations on other planets. Mars exploration will continue as planned through this decade, but the large rover planned for 2007 is delayed until 2009 in order to substitute nuclear for solar power and increase its lifetime from months to years. A fully competed Discovery-class Mars Scout mission will be flown in 2007.
The DPS calls upon Congress to support the President's proposed FY03 NASA budget. It builds on the strengths and successes of our planetary program. New nuclear technology for both power and propulsion will extend our reach and capabilities to the outermost regions of our Solar System while increasing our capabilities in the inner Solar System. The New Frontier program offers exciting opportunities, including restoration of missions to the outer solar system.
The DPS is the world's largest professional organization dedicated to the exploration of the Solar System.
San Antonio -- November 30, 2001 -- After a two-month evaluation, NASA has selected the "New Horizons" proposal, led by Southwest Research Institute (SwRI), to proceed with preliminary design studies for a mission to the Pluto-Kuiper Belt (PKB) system. The mission, including science payload, spacecraft, and launch vehicle, will examine the last unexplored planet in the solar system and move beyond Pluto to explore multiple objects in the Kuiper Belt. The mission will also make the next planned exploration of Jupiter and its moons.
Led by Principal Investigator Dr. S. Alan Stern, director of the SwRI Department of Space Studies, the winning proposal involves constructing and flying a complete mission, including development of the spacecraft, trajectory, science instruments, and an education and public outreach plan.
"We'll be exploring frontier worlds near the edge of the planetary system," says Stern, who is based in the SwRI Boulder, Colo., office. "This mission is likely to rewrite textbooks regarding the origin of the planets, the nature of the outer solar system, and even the origin of primitive materials that may have played a role in the development of life."
SwRI leads the New Horizons team, which also includes major partners at the Johns Hopkins University Applied Physics Laboratory of Laurel, Md.; Stanford University of Palo Alto, Calif.; Ball Aerospace Corp. of Boulder, Colo.; the NASA Goddard Space Flight Center of Greenbelt, Md.; and the Jet Propulsion Laboratory of Pasadena, Calif.
During the New Horizons feasibility study that occurred this summer, the team designed a spacecraft equipped with sensitive, miniaturized cameras, a radio science instrument, ultraviolet and infrared spectrometers, and space plasma experiments. The team believes this combination of science instruments is ideal to characterize the global geology and geomorphology of Pluto and its moon Charon, to map their surface compositions, and to characterize Pluto's atmosphere and its atmospheric escape rate. The feasibility study also showed the mission could save money using technologies for deep space exploration that are essentially off the shelf.
Congress has approved $30 million of fiscal year 2002 funds to conduct final design work of the spacecraft and science instruments and to contract the launch vehicle. For the mission to continue beyond 2002, the program must meet two conditions set by NASA. First, the team must pass a NASA-led "confirmation review" of its work. Second, Congress must approve additional funding.
"We couldn't be more pleased to be leading this pioneering space mission," says Dr. James L. Burch, vice president of the SwRI Space Science and Engineering Division. "We are happy to have such quality institutions participating on this mission and are confident of its success."
Pluto is the most distant planet known and the largest member of the Kuiper Belt. Kuiper Belt Objects -- a class of objects composed of material believed to have been left over after the formation of the other planets -- have never been exposed to the higher temperatures and solar radiation levels of the inner solar system. Pluto has large quantities of ices of nitrogen and simple molecules containing combinations of carbon, hydrogen, and oxygen that are the necessary precursors of life. The gases comprising these ices would be largely lost to space if Pluto had come close to the sun. Instead they remain on Pluto as a sample of the primordial material that set the stage for the evolution of the solar system as it exists today - -- including life.
With additional funding, the launch of New Horizons is expected to occur in January 2006, with the spacecraft arriving at Pluto between 2014 and 2018, depending on the selection of the launch vehicle. Along the way to Pluto, New Horizons will capitalize on a gravitational boost from Jupiter.
NASA has selected a team led by The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, MD, and Southwest Research Institute (SwRI) in San Antonio, TX, to develop the first mission to explore Pluto and the Kuiper Belt region beyond the distant planet.
Headed by Principal Investigator Dr. S. Alan Stern of SwRI, the New Horizons: Shedding Light on Frontier Worlds mission team also includes Ball Aerospace, Boulder, CO; Stanford University, Palo Alto, CA; NASA Goddard Space Flight Center, Greenbelt, MD; and a variety of other universities and research institutions. Thomas Coughlin is the project manager at APL, which will manage the mission for NASA and design, build and operate the New Horizons spacecraft. SwRI will lead the science team and guide development of the spacecraft's scientific instruments. Ball Aerospace and NASA Goddard will help develop the payload.
Aiming for a 2006 launch and arrival at Pluto before 2020, NASA officials say the mission must pass a confirmation review that will address significant risks such as schedule and technical milestones and regulatory approval for launch of the mission's nuclear power source. Funding must also be available; Congress provided $30 million in fiscal 2002 for the mission to procure a launch vehicle and start developing the spacecraft and science instruments, but no funding for subsequent years is included in the administration's budget plan.
Pluto is the most remote planet in the solar system; its elliptical orbit has an average distance of 3.66 billion miles (5.91 billion kilometers) from the sun - nearly 40 times the distance between Earth and the sun. The Kuiper Belt is a source of comets and believed to be the source of much of Earth's water and the simple chemical precursors of life.
"We'll explore frontier worlds near the edge of the planetary system," says Stern, who is also the director of SwRI's Department of Space Studies, Boulder. "This mission is likely to rewrite textbooks regarding the origins of the planets, the nature of the outer solar system, and even the origin of primitive materials that may have played a role in the development of life. We are very excited to be a part of this wonderful NASA mission."
NASA will work with Stern to further define mission costs and to finalize the design of the spacecraft and its accommodation of the instrument sets. New Horizons is planned for launch in January 2006 and, depending on the launch vehicle selected, would reach Pluto and its moon, Charon, in July of 2016 or 2018. On the way, the small, lightweight craft would pass Jupiter, using the giant planet's gravity as a slingshot toward Pluto and exploring the Jovian system.
The spacecraft team plans to use several proven subsystems already designed for other APL planetary missions, saving money while reducing risk and shortening the project's development schedule. New Horizons' remote-sensing instruments will characterize the global geology and geomorphology of Pluto and Charon, map their surface compositions and temperatures, and examine Pluto's atmosphere in detail. Encounters with Kuiper Belt Objects will occur after the Pluto-Charon flyby.
"The Kuiper Belt is an archeological dig into the early history of our solar system," says Dr. Andrew Cheng, New Horizons project scientist at APL. "It's full of small, icy, dirty and rocky objects that started to build into planets but, for some mysterious reason, stopped in mid-stride. It's a fascinating region."
Following the successful management model of NASA's Discovery Program, New Horizons is a principal investigator-led team representing academia, industry, NASA centers and other communities. In addition to Stern, Coughlin and Cheng, the management team includes Mission Director Dr. Robert Farquhar of APL and Science Payload Manager William Gibson of SwRI. NASA's Jet Propulsion Laboratory, Pasadena, CA, will provide navigation support, and tracking and communication services through NASA's Deep Space Network.
"Leading the first mission to Pluto is an exciting opportunity for the Applied Physics Laboratory," says APL Director Dr. Richard Roca. "We promise a rewarding mission for NASA and for avid space science supporters, such as Sen. Barbara Mikulski and the Maryland delegation, who have done so much to advance science and technology in the state."
New Horizons is the latest of several NASA projects on APL's roster. The Lab manages the Comet Nucleus Tour (CONTOUR), which launches in July 2002 to study at least two diverse comets, and Mercury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER), set to become the first spacecraft to orbit Mercury after launching in March 2004. APL also managed the Near Earth Asteroid Rendezvous (NEAR) mission - which included the first spacecraft to orbit and land on an asteroid - and recently secured a 12-year, $600 million contract for missions in NASA's Sun-Earth Connection program.
For more information on the Pluto mission, visit the New Horizons Web site at pluto.jhuapl.edu.
In November 2001, Congress inserted $30,000,000 into NASA's budget for a mission to Pluto in 2006. However, the funding at the moment is only for one year. Also, NASA's two existing radioisotope electrical generators are spoken for (for the Europa mission), and a Pluto mission needs one. So the battle isn't over.
Boulder, Colorado- September 27, 2001 -- A team led by the Southwest Research Institute (SwRI) and the Johns Hopkins University Applied Physics Laboratory (JHU APL) has just completed a NASA-funded, "Phase A" design study for a Pluto-Kuiper Belt mission. This team, called "New Horizons," was one of two selected by NASA's Office of Space Science early this summer and funded at a level of $450,000 to conduct Pluto-Kuiper Belt mission studies. The principal investigator of the New Horizons Pluto-Kuiper belt mission study is Dr. Alan Stern of SwRI. The New Horizons study team consists of over 20 scientific experts in Pluto and Kuiper Belt studies, along with almost 100 engineers and other personnel at SwRI, JHU APL, Stanford University, Ball Aerospace, and NASA's Goddard Space Flight Center.
Pluto is the most distant planet known and the largest member of the Kuiper Belt. Kuiper Belt Objects -- a class of objects composed of material left over after the formation of the other planets -- have never been exposed to the higher temperatures and solar radiation levels of the inner solar system. Pluto has large quantities of ices of nitrogen and simple molecules containing combinations of carbon, hydrogen, and oxygen that are the necessary precursors of life. These ices would be largely lost to space if Pluto had come close to the sun. Instead they remain on Pluto as a sample of the primordial material that set the stage for the evolution of the solar system as it exists today, including life.
"NASA asked us to perform a detailed feasibility study for flying a mission to explore Pluto and its giant satellite Charon, and to then go on to the Kuiper Belt." Says Principal Investigator Stern, "We found the mission to be feasible with technologies that are essentially off the shelf for deep space exploration. We also found that a launch as soon as December 2004 can be accomplished."
The New Horizons team studied flying a spacecraft equipped with sensitive, miniaturized cameras, a radio science instrument, ultraviolet and infrared spectrometers, and space plasma experiments. The study team found that this combination of instruments is essentially ideal to characterize the global geology and geomorphology of Pluto and its moon Charon, to map their surface compositions, and to characterize Pluto's atmosphere and its atmospheric escape rate. "These are the very objectives NASA set forth as goals for the Pluto-Kuiper Belt mission," says New Horizons Payload Manager Mr. William‹dQ©Ò"åûû\ívÖqÃùÁ\~¸›ù¿–á1¬fö/§® (ØA|óèq†ï7±ö 5ùMÎé§ …_ÙHqY0˜jw"<:v…ä‡x0ê®qUZ‚™øÑŸüÍnölò"z‰E±(<û ” ›fRjrùæ¹O³›"²êg¹-cã,ä 铧¦Ü‚5oLéúv[´l úÓ.=Ëy)G~ºá*Êù®IFü¿›/¥ˆ¹ÔŸŒè ˜Ív`ºY·›Ãþq^åuÜ@îõïöE7ãuÁéÅÅÓ{‹ê…ä.L¸p|ó4i*¿’‡¸è`»5ÑwWï7Á¸T¦³:¥èÇ@Ïéèdå2Áñ¡þÛ{`ðÜ4+1cw-aþ½¬æöØ–Dèåî>s«è¥´åߜ×VOÏŸ‹¥îÊ–—é¡I æºû T¡¶ÿÞ)åZQé²ä7þ‰Ó<9ts and possibly other properties similar to those of Pluto. It has been proposed to assign Pluto a number in a technical catalogue or list of such Trans-Neptunian Objects (TNOs) so that observations and computations concerning these objects can be conveniently collated. This process was explicitly designed to not change Pluto's status as a planet.
A Working Group under the IAU Division of Planetary Systems Sciences is conducting a technical debate on a possible numbering system for TNOs. Ways to classify planets by physical characteristics are also under consideration. These discussions are continuing and will take some time. The Small Bodies Names Committee of the Division has, however, decided against assigning any Minor Planet number to Pluto.
3: From time to time, the IAU takes decisions and makes recommendations on issues concerning astronomical matters affecting other sciences or the public. Such decisions and recommendations are not enforceable by national or international law, but are accepted because they are rational and effective when applied in practice. It is therefore the policy of the IAU that its recommendations should rest on well-established scientific facts and be backed by a broad consensus in the community concerned. A decision on the status of Pluto that did not conform to this policy would have been ineffective and therefore meaningless. Suggestions that this was about to happen are based on incomplete understanding of the above.
The mission of the IAU is to promote scientific progress in astronomy. An important part of this mission is to provide a forum for debate of scientific issues with an international dimension. This should not be interpreted to imply that the outcome of such discussions may become official IAU policy without due verification that the above criteria are met: The policy and decisions of the IAU are formulated by its responsible bodies after full deliberation in the international scientific community.
Johannes Andersen
General Secretary, IAU
For more information, contact the IAU Secretariat (URL: http://www.iau.org and address below), or the Division President, Prof. Michael A'Hearn, University of Maryland, USA (Tel: (301) 405 6076; Fax: (301) 314 9067; E-mail: ma@astro.umd.edu).
[from the Division of Planetary Sciences of the American Astronomical Society]
Colleagues,
No doubt, you are aware of the recent media attention implying that Pluto has been "officially" downgraded from planetary status. This was stimulated in large part by a suggestion by the Minor Planet Center to assign the minor planet number 10000 to Pluto in conjunction with the numbering of some Trans-Neptunian Objects. The Small Bodies Names Committee (SBNC) of IAU Commission 20 has been discussing this issue for several months, as has the Executive Committee of IAU Division III (Planetary Systems Sciences). It should be emphasized that, in spite of media perceptions, no action or decision has yet been taken. The number 10000 will likely be reached for the numbered asteroids within a few weeks. Mike A'Hearn, as President of IAU Division III, has established a web page with background information which also solicits input from the astronomical community:
http://www.ss.astro.umd.edu/IAU/div3/
The DPS committee believes that this situation is harmful to our profession and will become more so if not put quickly to rest. The public is confused, acrimonious rifts are being created within our community and many of our colleagues are being diverted from productive work to counter what they perceive to be an alarming and unnecessary crisis. We have therefore adopted the following brief position statement, which will be forwarded to the appropriate IAU committees:
"The Committee of the Division for Planetary Sciences of the American Astronomical Society is opposed to assigning a minor planet number to Pluto. This action would undoubtedly be viewed by the broader scientific community and the general public as a "reclassification" of Pluto from a major planet to a minor planet. We feel that there is little scientific or historical justification for such an action."
We urge DPS members to visit the above web page and express your opinions. Michael A'Hearn (ma@astro.umd.edu) is President of IAU Div. III and Chair of the Small Bodies Nomenclature Committee, and can relay messages to appropriate others in the IAU.
Don Yeomans, Division of Planetary Sciences/Am Astron Soc Chairman and the other members of the DPS Committee
[Postscript from another message from Don Yeomans: Many of us have been asked when the Planet Pluto will once again have the largest heliocentric distance of any of the nine planets. JPL's Myles Standish notes that on 1999 Feb. 11 at 10:09 ET, Pluto's distance will exceed that of Neptune's. This result is based upon JPL's Planetary ephemeris DE405 and the time refers to Pluto and Neptune themselves rather than their respective barycenters (the latter time would be 09:40).]
Note the additional objection from
Deborah Pasachoff:
We can now note the nine planets from the initial letters of "My Very Educated
Mother Just Sent Us Nine Pizzas." If we demote Pluto, the mnemonic would become
"My Very Educated Mother Just Sent Us Nothing," which is obviously undesirable.