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New Horizons: Hubble Hunts KBOs

My guess is that the public thinks of the Hubble Space Telescope largely in relation to deep space objects. The Hubble Ultra Deep Field is a case in point, a region of the sky in the constellation Fornax that is no more than a tenth of the width of a full moon, but one that contains 10,000 galaxies. An image of the HUDF augmented by near-ultraviolet data has had considerable play in the media, showing star birth in galaxies five to ten billion years ago. It’s too lovely not to show here.


Image: The Hubble Ultra Deep Field with near-ultraviolet data, a false-color image that is the result of data acquisition from 841 orbits between 2003 and 2012. Credit: NASA/ESA/Caltech/Arizona State.

The HUDF attests to Hubble’s range, but we also know from Hubble’s studies of objects in our own Solar System that it can support ongoing planetary missions. Astronomers will now use the space observatory to help find tiny objects against the background of an immense starfield in Sagittarius. After consideration of the mission and the value of the data it will return, the Hubble Space Telescope Time Allocation Committee has recommended that the instrument be used to search for a Kuiper Belt Object that New Horizons can visit after its flyby of Pluto/Charon in 2015, a search contingent upon results of a pilot observation program using Hubble data.

We have two Voyagers still sending data as they push into interstellar space, but only New Horizons has a fully functioning set of instruments and the capability of making the necessary course alterations to perform a KBO flyby. The problem has been to identify the target, a hunt that could begin no earlier than 2011 because KBO candidates needed to be converging on the region of space that New Horizons can reach after the Pluto/Charon encounter. The 8.2-meter Subaru Telescope in Hawaii and the 6.5-meter Magellan Telescopes in Chile have so far been deployed on the task but it looks like it will take Hubble to make the call.

For of the roughly fifty new KBOs that the Subaru and Magellan instruments have thus far identified, none is within range of the spacecraft’s ability to maneuver. This is an extremely difficult search field, one that looks into the plane of the galaxy toward Sagittarius, and astronomers are searching for something that is both small and likely to be as dark as charcoal. But finding a target is important — the Kuiper Belt consists of debris from the Solar System’s formation, and we’ve never had the opportunity to get a close-up look at one of these objects.


If Subaru and Magellan haven’t been able to find the right KBO, Hubble will try something different, turning at the rate that KBOs are predicted to move against the background stars. As this Space Telescope Science Institute news release explains, the result will be that KBOs will show up as pinpoint objects amidst a swarm of streaky background stars. Assuming the initial test observations — 40 orbits of Hubble observing time — show that the telescope can find at least two KBOs of the specified brightness, additional observing time covering a period of 156 orbits will be allotted to search a field of view the angular size of the full Moon.

Let’s wish Hubble success because New Horizons is the successor to the Voyagers, like them involved in a journey that should captivate and inspire our culture. The more science we can get out of it, the better, even though putting a payload past Pluto/Charon is itself a grand accomplishment. As for Hubble, its efforts on behalf of New Horizons point to its previous discovery of four small moons in the Pluto/Charon system as well as its search for dust rings that might have compromised the mission. Just as Hubble has proven its worth again and again in terms of planetary science (and don’t forget its contributions to the Dawn mission), we can hope for equally impressive accomplishments from the coming James Webb Space Telescope.


Comments on this entry are closed.

  • ljk June 17, 2014, 9:42

    “We have two Voyagers still sending data as they push into interstellar space, but only New Horizons has a fully functioning set of instruments and the capability of making the necessary course alterations to perform a KBO flyby.”

    I have two questions: Are there any KBOs that the Voyager probes might be able to reach and what could they do in terms of scientific investigation if such a thing is possible?

  • Paul W June 17, 2014, 10:38

    Yes, that photo is awesome, and Hubble has been wonderful beyond belief.
    It startled me to realize that there are 2 additional “Hubble” quality telescopes mothballed, never used. They were donated by the NSA when spy technology got better than even these telescopes could deliver (looking the “wrong” way!)

    I think about how many additional agendas in near and deep space could be researched if these telescopes were up in orbit. Does anyone have any specific knowledge of these devices? I assume that, as in everything, No One has any money, and these will sit somewhere until Hubble fails, and even then no one will have any funds to launch them.

  • Paul Gilster June 17, 2014, 12:06

    ljk writes:

    I have two questions: Are there any KBOs that the Voyager probes might be able to reach and what could they do in terms of scientific investigation if such a thing is possible?

    I suppose technically anything the Voyagers would encounter wouldn’t be a KBO — I keep seeing 50 AU cited as the outer limit of the Kuiper Belt — but whatever we called an object out there, it would be interesting to visit it. I’m not aware that either Voyager has any course-altering capability at this point, but maybe people better informed on this than I can comment.

    Re the mirror situation that Paul W mentions, an older Centauri Dreams post with a bit of background is here:


  • CharlesJQuarra June 17, 2014, 15:51

    The biggest problem with the Voyagers is that the onboard cameras have been turned off and they can’t be turned on easily: http://voyager.jpl.nasa.gov/faq.html

    Which is a pity really, since from the weekly reports it seems that there are still about 20Kg of propellant on each spaceship (although no idea how much delta-V those could actually translate to): http://voyager.jpl.nasa.gov/mission/weekly-reports/

  • Brian Swiderski June 17, 2014, 22:17

    Paul W:

    I assume that, as in everything, No One has any money

    There is tons of money, but it basically just sits there in rich people’s bank accounts and hedge funds. If just a tiny fraction of it were brought to bear for space exploration, at least our robotic probes would be swarming all over the solar system. But no – all the real power is held by sociopaths and dullards who would throw away a trillion dollars on an illegal war for no reason and then begrudge pennies on the dollar for expanding humanity’s horizons.

  • Glaas June 18, 2014, 1:43

    “Are there any KBOs that the Voyager probes might be able to reach and what could they do in terms of scientific investigation if such a thing is possible?”

    Voyager might detect a KBO is if it is gets close enough and is massive enough to measurably alter the probe’s trajectory. The “Pioneer anomaly” was first thought to be such an event, but it was caused by the probes own heat emissions.

    Voyager’s camera broke when the heating shut down. KBOs likely don’t have enough magnetic field to be detected by the working instrument. And not much data could be transmitted to Earth anyway.

  • ljk June 18, 2014, 9:37

    While images would be nice, other aspects of a KBO could still be determined by the still functioning instruments aboard the Voyagers:


    ISEE-3, now wending its way towards Earth, examined two comets and that was not even its original mission purpose. Plus the Voyagers are all we’ve got out there right now that are still functioning.

  • ljk June 18, 2014, 10:20

    Mariner 2 and 5 also examined Venus in 1962 and 1967, respectively, returning important information about the shrouded world without having cameras.

    The ESA comet probe Giotto returned data on comet Grigg-Skjellerup in 1992 despite its camera being damaged beyond use by the debris of comet Halley in 1986.

  • Glaas June 18, 2014, 10:55

    A magnetic-something anomaly would be phantastically mysteriously big news for Voyager! But ancient icy clumps out there probably don’t have much magnetic acticity. Empty space out there seems to be boringly well understood by science today. It’s sooo empty. We won’t find anything if we don’t aim for something. Which is why New Horizons needs to get a secondary target soon.

    Future probes should be designed to return science data for a century! That’s a lesson we’ve learned from Voyager, but wasn’t much thought of when those probes were designed in the 1970s. The ambition back then seems to have been to conserve nothing but a carved golden plate somewhere out there in our millenia. Next time we pass by Neptune, it should be with a century probe.

  • ljk June 18, 2014, 10:55

    Beyond Apollo

    Pluto: Doorway to the Stars (1962)

    BY DAVID S. F. PORTREE 06.14.14 | 2:10 AM |

    In just about a year, the New Horizons spacecraft will begin daily observations of the dwarf planet Pluto. A month later, on 14 July 2015, the piano-sized 478-kilogram probe will fly by Pluto at a nominal distance of only 10,000 kilometers moving at a velocity of 14 kilometers per second. At that speed and distance, New Horizons will briefly return images of Pluto in which objects as small as 50 meters wide could be visible.

    Pluto was discovered in 1930, during Lowell Observatory’s hunt for a planet beyond Neptune. The observatory, founded in 1894 by wealthy Bostonian Percival Lowell to find proof of intelligent life on Mars, had begun its search for a trans-Neptunian planet in 1906.

    The search for Planet X (as Percival Lowell dubbed his hypothetical world) was at least partly motivated by the growing disdain with which Lowell’s Mars theories were greeted by professional astronomers. Lowell was eager that his observatory should be seen to be credible; discovery of a new planet would, he felt, restore and cement its eroded credibility.

    Full article here:


    To quote:

    George Peterson Field was the pen name of Dr. Robert Forward. Safely hidden behind the protective cloak of his nom de plume, the newly minted Ph.D. physicist speculated in a “science fact” article in the December 1962 issue of Galaxy science fiction magazine that Pluto was a gift from a “Galactic Federation.”

    He began by calculating that a body about the size of Mercury but with six times the mass of Earth would be so dense that it would have to be made of the collapsed matter found only in certain dwarf stars. Such an object could not exist naturally; unrestrained by the massive gravity of a dwarf star, it should have exploded long ago. Therefore, Forward asserted, Pluto must be artificial.

    He suggested that Pluto was in fact a “gravity catapult.” He wrote that “it would have to be whirling in space like a gigantic, fat smoke ring, constantly turning from inside out.” A spacecraft that approached the ring’s center moving in the direction of its spin would be dragged through “under terrific acceleration” and ejected from the other side.

  • ljk June 18, 2014, 15:49

    Glaas said on June 18, 2014 at 10:55:

    “A magnetic-something anomaly would be phantastically mysteriously big news for Voyager! But ancient icy clumps out there probably don’t have much magnetic acticity. Empty space out there seems to be boringly well understood by science today. It’s sooo empty. We won’t find anything if we don’t aim for something. Which is why New Horizons needs to get a secondary target soon.”

    That is one hope, if a Voyager probe could fly close enough to a KBO to be influenced by its mass, which would certainly determine a few things about its structure.

    Deep space is not that empty: There is enough activity going on where Voyager 1 is for us to determine when it left one sphere of our planetary system’s influence, though I hesitate to say it is truly in interstellar space.

    We don’t know what other surprise await us way out there where those probes are, which is why we should thank our lucky scientific stars every day that they keep functioning and returning data to us.

    Glaas then said:

    “Future probes should be designed to return science data for a century! That’s a lesson we’ve learned from Voyager, but wasn’t much thought of when those probes were designed in the 1970s. The ambition back then seems to have been to conserve nothing but a carved golden plate somewhere out there in our millenia. Next time we pass by Neptune, it should be with a century probe.”

    Hard to argue about having probes last a century or more. We will certainly need their kind for interstellar missions.

    About the golden records on the Voyagers, that was not NASA’s idea although of course they had to approve of them. The probe team hoped they would make it to Jupiter and Saturn; anywhere else was a bonus. When Sagan et al wrote the literal book about the records, titled Murmurs of Earth in 1978, they considered the Voyagers reaching Uranus if they survived but did not include Neptune at the time!

    Same with Pioneer 10 and 11, our first vessels to reach solar system escape velocity. No one at NASA publicly considered any kind of message or information package or any real tribute to such an amazing technological achievement. It took a small outside group to eventually get the famous Pioneer Plaque affixed to those probes.

    NASA also thought the Pioneers would not last much beyond their initial missions, to flyby Jupiter, but Pioneer 11 went on to Saturn in 1979 and Pioneer 10 kept transmitting until 2003.

    Thankfully I think experience has taught NASA to expect more from their deep space probes than just returning data on the target world.

  • ljk June 20, 2014, 10:52

    Hubble Space Telescope Starts Search For Kuiper Belt Objects As New Horizons Races Towards Pluto

    By Leonidas Papadopoulos

    With the clock ticking towards NASA’s New Horizons upcoming Pluto flyby in July of next year, time has been running out for the discovery of a suitable Kuiper Belt Object that the spacecraft could study, following its close encounter with the dwarf planet.

    Having systematically searched the skies for years with some of the biggest telescopes on the ground to no avail, the mission’s science team has just been given the green light to use the Hubble Space Telescope, whose superior observing capabilities represent the last best chance for assuring a successful extended mission phase for the New Horizons spacecraft.

    The study of at least one member of the hundreds of thousands of icy planetesimals that are believed to reside in the vast region beyond the orbit of Neptune, known as the Kuiper Belt, had been one of the main science goals for all the robotic mission concepts to Pluto that were under consideration by NASA during the 1990s, like the Pluto Fast Flyby and Pluto Kuiper Express.

    Based on these previous mission proposals which were ultimately cancelled by the space agency due to budget constrains, New Horizons retained the exploration of the Kuiper Belt as a main science objective, provided that a suitable KBO located close enough to the spacecraft’s flight path through the Pluto system, could be discovered.

    To that end, following the spacecraft’s launch in 2006, the mission’s science team implemented an extensive observing campaign utilising some of the largest ground-based telescopes, like the twin 6.5-m Magellan Telescopes in Chile and the 8.2-m Subaru and 3.6-m Canada–France–Hawaii Telescopes on Mauna Key in Hawaii. Yet, even though they had been able to discover a total of 52 candidate KBOs in the same area of the sky as Pluto, scientists found none that laid close enough for New Horizons to visit.

    Full article here:


    To quote:

    The optimism showcased by the New Horizons team regarding the outcome of the ongoing KBO search isn’t unwarranted however. These new observations by Hubble, are the latest in a long series of past Solar System observations by the space telescope that have led to important, groundbreaking discoveries, like Pluto’s four smaller moons, Nix, Hydra, Kerberos and Styx, which were discovered during the last decade, and had all gone undetected by previous searches with ground-based observatories. Contrary to the saying that past performance is not necessarily indicative of future results,that is so prevalent in the financial sector, Hubble’s past accomplishments are indicative of its unsurpassed abilities as an astronomical observatory to probe deep into the uncharted territory that is the vast expanse beyond Neptune.

    “The planned search for a suitable target for New Horizons further demonstrates how Hubble is effectively being used to support humankind’s initial reconnaissance of the Solar System,” says Mountain. “Likewise, it is also a preview of how the powerful capabilities of the upcoming James Webb Space Telescope will further bolster planetary science. We are excited by the potential of both observatories for ongoing Solar System exploration and discovery.”

  • ljk June 24, 2014, 11:53

    Greetings from Earth! NASA Spacecraft to Carry Message for Aliens

    By Nola Taylor Redd, Space.com Contributor | June 23, 2014 04:44 pm ET

    A NASA probe that’s expected to leave the solar system after it finishes its mission at Pluto and beyond will carry a message intended for any alien life-form that comes across it in the far future.

    When NASA’s New Horizons mission completes its study of Pluto in the summer of 2015, data from Earth will stream to the spacecraft to create a digital record that it will carry with it beyond the solar system. The record echoes the Golden Record carried by NASA’s Voyager 1 and Voyager 2 spacecraft in the 1970s and the plaques onboard the Pioneer spacecraft.

    Jon Lomberg, who served as design director for NASA’s Voyager Golden Record, worked with late astronomer Carl Sagan and four others to select a series of sounds and images that were combined on a gramophone record as representative of Earth.

    When Lomberg realized that New Horizons would become the next object to leave the solar system, he launched an online petition to include a similar message for New Horizons, called the One Earth Message.

    The only problem was that New Horizons launched several years earlier, in 2006.

    Instead of creating a physical artifact, Lomberg suggested creating a digital one: streaming data to the spacecraft once it had completed its study of Pluto and its moon Charon. He referred to it as a “digital Voyager record 2.0.”

    “In a way, the history of long-term space message artifacts recapitulates the history of communications technology,” Lomberg said.

    Full article here:


    To quote:

    Unlike previous records, the information on board New Horizons will not have to remain static. As long as the craft remains in communication with Earth, the message has the potential to be upgraded as the status of the planet changes.

    Although the spacecraft may never be found by extraterrestrials and its message may never be deciphered, Lomberg emphasized that the process itself has the potential to bring people together and reflect on what it means to be part of a global community.

    “For almost 40 years, people have been inspired by the Voyager record, a portrait of the Earth in 1977,” Lomberg said. “The world is very different now, and this new message will reflect the hopes and dreams of the second decade in the 21st century. It will inspire young people’s interest in science and ignite the imagination of all ages. We hope it will be an example of global creativity and cooperation, something that the entire planet can share as a cooperative venture, made possible by the new science of crowdsourcing.”

    You can learn more about the One Earth project at:


  • ljk July 2, 2014, 10:46

    Two Kuiper Belt objects found: Hubble to proceed with full search for New Horizons targets

    Date: July 1, 2014

    Source: Space Telescope Science Institute (STScI)

    Summary: Planetary scientists have successfully used the Hubble Space Telescope to find two Kuiper Belt objects for NASA’s New Horizons mission to Pluto. After the marathon probe zooms past Pluto in July 2015, it will travel across the Kuiper Belt — a vast rim of primitive ice bodies left over from the birth of our solar system 4.6 billion years ago. If NASA approves, the probe could be redirected to fly to a Kuiper Belt object and photograph it up close.

    Full article here:


  • ljk July 14, 2014, 10:01

    The Next Mission to Pluto

    By Andrew Lepage

    July 14, 2014

    On July 14, 2015 – one year from today – NASA’s New Horizons spacecraft will make its closest approach to the dwarf planet Pluto after a long voyage of 9½ years. Even though humanity has yet to see what the instruments of New Horizons will discover about this distant world and its family of moons, now is as good as time as any to start thinking seriously about the next mission to Pluto. Given the infrequent availability of low-energy launch opportunities and the long flight times to Pluto coupled with the lengthy process of proposing planetary missions, gaining the required support and funding as well as actually building the hardware, it will likely be decades before we visit Pluto again.

    Full article here:


    To quote:

    New models of the seasonal evolution of Pluto’s atmosphere that agree better with measurements of how it has changed over the past quarter century suggest, however, that Pluto’s atmosphere will not collapse as predicted and might even thicken towards a maximum value around 2040 (near the time of this proposed Pluto follow on encounter) depending on the dwarf planet’s inventory of volatile ices and the properties of the atmosphere.

    No matter which of the models developed over the last 30 years proves to be correct, it is clear that Pluto’s atmosphere and surface deposits vary on times scales of decades as a result of the interplay of the seasons and the variations in its distance from the Sun. A new set of close up observations of Pluto almost a quarter of a century after New Horizons’ will provide vital clues about the seasonal changes on Pluto. And given the long orbital period of this distant world, this will be humanity’s only chance to observe Pluto during this crucial phase of the northern summer for another 248 years.

    In addition to changes on Pluto that would be observed, a follow on mission to this distant world will also benefit from almost a quarter century’s worth of advances in technology and remote sensing techniques. The instrument payload of New Horizons, as impressive as it is, did not include everything scientists would have wished and was limited by the available payload capabilities of the launch vehicle chosen for a less-than-ideal launch window to Pluto.

    Advances in technology coupled with a more favorable launch window in 2028/29 should allow a more massive and much more capable set of miniaturized instruments to be carried by New Horizons’ successor. Advances in data storage and space communication technologies should also allow more data to be collected and transmitted back to Earth faster than is possible with New Horizons.

  • ljk September 17, 2014, 10:05

    ‘Global Selfie’ Project Will Beam Earthling Message to Space

    By Tanya Lewis, Staff Writer | September 15, 2014 05:45 pm ET

    WAIMEA, Hawaii — A new project aims to send a special message from Earth — a type of global “selfie” — into space, by uploading it to a spacecraft traveling through the cosmos on its way to Pluto.

    Led by Hawaii-based artist Jon Lomberg, the so-called One Earth project aims to beam pictures, sounds and other data representing the planet’s inhabitants to NASA’s New Horizons spacecraft.

    “Why not make a crowdsourced self-portrait of Earth?” Lomberg told a crowd Friday (Sept. 12) here at HawaiiCon, a science, sci-fi and fantasy convention on the Big Island of Hawaii. Sci-fi celebrities from popular TV series and local astronomy experts mingled with convention attendees at the three-day event.

    Full article here:


    To quote:

    NASA accepted the proposal and has agreed to set aside 100MB for the crowdsourced content on the New Horizons probe, after the spacecraft finishes capturing images of Pluto. So now that the project has been approved, where do you start?

    Lomberg envisions having people from around the world, including kids, submit photos and other forms of media online. But he also wants to include contributions from people who don’t have access to the Internet, such as tribes in the Kalahari Desert in Africa.

    Submissions could span a range of subjects, from humans to other animals to objects within the solar system. But Lomberg and his team also want to include images that reveal the dark side of Earth, such as pictures of famine or the atomic bomb. To deny humanity’s problems would create a dishonest picture of Earth, Lomberg said.

    “We don’t know how long [the message] will last,” and most likely, it will never be found, Lomberg said. But besides E.T., the message has another audience: the people of Earth, he said.

  • ljk October 15, 2014, 15:04

    Finally! New Horizons has a second target

    Posted by Emily Lakdawalla

    2014/10/15 18:02 UTC

    Topics: trans-neptunian objects, New Horizons, pretty pictures, New Horizons KBO target, mission status

    What a huge relief: there is finally a place for New Horizons to visit beyond Pluto. A team of researchers led by John Spencer has discovered three possible targets, all in the Cold Classical part of the Kuiper belt.

    New Horizons will most likely visit one named “PT1” for “[New Horizons] potential target 1.” PT1 has been imaged four more times by Hubble since its discovery, and those followup images have provided enough information on its orbit for four independently working teams to determine that New Horizons will be able to fly close past it in January 2019.

    It is probably about 30-45 kilometers in diameter and is easily reachable with New Horizons’ limited fuel budget; targeting it will require only about 35% of the spacecraft’s remaining fuel. New Horizons will have to fly an additional billion kilometers beyond Pluto in order to reach it where it orbits 43.4 AU away from the Sun.

    Full article here: