Pluto Archives

February 14, 2013December 23, 2015 by Jason Major

A Valentine From Voyager

Venus, Earth, Jupiter, Saturn, Uranus and Neptune as seen by Voyager 1 on Valentine's Day in 1990

On February 14, 1990, after nearly 13 years of travel through the outer Solar System, NASA’s Voyager 1 spacecraft crossed the orbit of Pluto and turned its camera around, capturing photos of the planets as seen from that vast distance. It was a family portrait taken from over 4.4 billion kilometers away — the ultimate space Valentine.

Who says astronomy isn’t romantic?

Full mosaic of Voyager 1 images taken on Feb. 14, 1990 (NASA/JPL)

“That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives… There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world.”

– Carl Sagan

It was the unique perspective above provided by Voyager 1 that inspired Carl Sagan to first coin the phrase “Pale Blue Dot” in reference to our planet. And it’s true… from the edges of the solar system Earth is just a pale blue dot in a black sky, a bright speck just like all the other planets. It’s a sobering and somewhat chilling image of our world… but also inspiring, as the Voyager 1 and 2 spacecraft are now the farthest human-made objects in existence — and getting farther every second. They still faithfully transmit data back to us even now, over 35 years since their launches, from 18.5 and 15.2 billion kilometers away.

The Voyagers sure know the value of a long-term relationship.

See more news from the Voyager mission here.

February 11, 2013April 26, 2016 by Jason Major

Help Name Pluto’s Newest Moons!

Pluto's known system of moons (NASA/ESA/M. Showalter))

Today marks seven months since the announcement of Pluto’s fifth moon and over a year and a half since the discovery of the one before that. But both moons still have letter-and-number designations, P5 and P4, respectively… not very imaginative, to say the least, and not really fitting into the pantheon of mythologically-named worlds in our Solar System.

Today, you can help change that.

According to the New Horizons research team, after the discovery of P4 in June 2011 it was decided to wait to see if any more moons were discovered in order to choose names that fit together as a pair, while a*lso following accepted IAU naming practices. Now, seven months after the announcement of P5, we think a decision is in order… and so does the P4/P5 Discovery Team at the SETI Institute.

"Hey, I can be democratic about this!" — “Hey, I can be democratic about all this!”

Today, SETI Senior Research Scientist Mark Showalter revealed a new poll site, Pluto Rocks, where visitors can place their votes on a selection of names for P4 and P5 — or even write in a suggestion of their own. In line with IAU convention these names are associated with the Greek and Roman mythology surrounding Pluto/Hades and his underworld-dwelling minions.

“In 1930, a little girl named Venetia Burney suggested that Clyde Tombaugh name his newly discovered planet ‘Pluto.’ Tombaugh liked the idea and the name stuck. I like to think that we are doing honor to Tombaugh’s legacy by now opening up the naming of Pluto’s two tiniest known moons to everyone.”

– Mark Showalter, SETI Institute

As of the time of this writing, the ongoing results look like this:

Results of Pluto Rocks voting as of Feb. 11, 2013 at 10 am EST (15:00 UT)

Do you like where the voting is headed? Are you hellishly opposed? Go place your vote now and make your opinion count in the naming of these two distant worlds!

(After all, New Horizons will be visiting Pluto in just under two and a half years, and she really should know how to greet the family.)

Voting ends at noon EST on Monday, February 25th, 2013.

The SETI team welcomes you to submit your vote every day, but only once per day so that voting is fair.

UPDATE: On Feb. 25, the final day of voting, the tally is looking like this:

PlutoRocks results as of Feb. 25, 2013 - Vulcan is in the lead, thanks to publicity from Mr. William Shatner — PlutoRocks results as of Feb. 25, 2013 – Vulcan is in the lead, thanks to publicity from Mr. William Shatner

Thanks in no small part to a bit of publicity on Twitter by Captain Kirk himself, Mr. William Shatner (and support by Leonard Nimoy) “Vulcan” has made the list and warped straight to the lead. Will SETI and the IAU honor such Trek fan support with an official designation? We shall soon find out…

January 16, 2013December 23, 2015 by Jason Major

New South Pole Marker Honors Planets, Pluto, and Armstrong

The new geographic South Pole marker that stands at 90º S latitude. (Credit: Jeffrey Donenfeld)

Because the Amundsen-Scott South Pole Station sits atop a layer of moving ice almost 2 miles thick, the location of the marker for the Earth’s geographic South Pole needs to be relocated regularly. Tradition has this done on New Year’s Day, and so this past January 1 saw the unveiling of the newest South Pole marker: a beautiful brass-and-copper design created by Station machinist Derek Aboltins.

The top of the marker has seven small discs that represent the planets in the positions they would be in on Jan. 1, 2013, as well as two larger discs representing the setting Sun and Moon. Next to the Moon disc are the engraved words “Accomplishment & Modesty,” a nod to the first man on the Moon.

“This was a reference to honor Neil Armstrong, as he passed away when I was making this section with the moon,” Aboltins said.

And for folks who might think the planet count on the new marker is one too few, a surprise has been tucked away on the reverse side.

“For those of you who still think Pluto should be a planet, you’ll find it included underneath, just to keep everyone happy,” Aboltins said. “Bring back Pluto, I say!”

And so, on the underside of the marker along with the signatures of South Pole Station researchers and workers, is one more disc — just for the distant “demoted” dwarf planet.

Underside of the South Pole marker (Credit: Jeffrey Donenfeld)

“For those of you who still think Pluto should be a planet, you’ll find it included underneath, just to keep everyone happy!”

– Derek Aboltins, designer and machinist

(See high resolution versions of these images here.)

The marker was placed during a ceremony on the ice on Jan. 1, during which time the previous flag marker was removed and put into its new position.

(Photo credit: Jeffrey Donenfeld)

According to The Antarctic Sun:

“Almost all hands were present for the ceremony, including station manager Bill Coughran, winter site manager Weeks Heist, and National Science Foundation representative Vladimir Papitashvili. The weather was sunny and a warm at just below minus 14 degrees Fahrenheit.”

(Even though it’s mid-summer in Antarctica, “warm” is clearly a relative term!)

Read more about this and other Antarctic news on The Antarctic Sun site, and see more photos from Antarctica by Jeffrey Donenfeld here.

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Named for explorers Roald Amundsen and Robert F. Scott, who attained the South Pole in 1911 and 1912, the Amundsen-Scott South Pole Station stands at an elevation of 2,835 meters (9,306 feet) on Antarctica’s ice sheet, which is about 2,700 meters (9,000 feet) thick at that location. The station drifts with the ice sheet at about 10 meters (33 feet) each year. Research is conducted at the station in the fields of astronomy, astrophysics, glaciology, geophysics and seismology, ocean and climate systems, biology, and medicine.

November 21, 2012December 23, 2015 by Jason Major

Makemake’s Mysteriously Missing Atmosphere

Artist’s impression of the surface of Makemake, a dwarf planet beyond Pluto (ESO/L. Calçada/Nick Risinger)

It turns out there’s no air up there: the distant dwarf planet Makemake is surprisingly lacking in an atmosphere, according to findings made by astronomers using telescopes at ESO’s La Silla and Paranal observatories.

An international team of astronomers used the mountaintop telescopes to observe Makemake as it passed in front of a faint background star in April 2011, a brief stellar occultation that lasted only about a minute. By watching how the starlight was blotted out by Makemake, measurements could be made of the dwarf planet’s size, mass and atmosphere — or, in this case, its lack thereof… a finding which surprised some scientists.

“As Makemake passed in front of the star and blocked it out, the star disappeared and reappeared very abruptly, rather than fading and brightening gradually. This means that the little dwarf planet has no significant atmosphere,” said team leader José Luis Ortiz of the Instituto de Astrofísica de Andalucía in Spain. “It was thought that Makemake had a good chance of having developed an atmosphere — that it has no sign of one at all shows just how much we have yet to learn about these mysterious bodies.”

First discovered in 2005, Makemake is an icy dwarf planet about 2/3 the diameter of Pluto — and 19 AU further from the Sun (but not nearly as far as the larger Eris, which is over 96 AU away.) It was thought that Makemake might have a tenuous, seasonal atmosphere similar to what has been found on Pluto, but it now appears that it does not… at least not in any large-scale, global form.

Due to its small size, sheer distance and apparent lack of moons, making scientific observations of Makemake has been a challenge for astronomers. The April 2011 occultation allowed measurements to be made — even if only for a minute — that weren’t possible before, including first-ever calculations of the dwarf planet’s density and albedo.

As it turns out, Makemake’s albedo is about 0.77 — comparable to that of dirty snow… a reflectivity higher than Pluto’s but lower than that of Eris. Its density is estimated to be 1.7 ± 0.3 g/cm³, indicating a composition of mostly ice with some rock.

“Our new observations have greatly improved our knowledge of one of the biggest [icy bodies], Makemake — we will be able to use this information as we explore the intriguing objects in this region of space further,” said Ortiz.

New Horizons May Need to ‘Bail Out’ to Dodge Debris, Rings and Moons in the Pluto System

Artist’s concept shows the New Horizons spacecraft during its 2015 encounter with Pluto and its moon, Charon. Credit: JHUAPL/SwRI

Since the New Horizons spacecraft left Earth back in 2006, there are a few things we know about the Pluto system now that we didn’t know then. For instance, it was discovered Pluto has two additional small moons – P4 and P5 — and Alan Stern, New Horizons Principal Investigator, said Pluto may have a large system of moons to be discovered as the spacecraft gets closer. There are also comets, possibly more dwarf planets and other objects out in the Kuiper Belt region where Pluto orbits.

“That’s exciting,” Stern said, “but this is a mixed story.”

Stern told Universe Today that while the spacecraft possibly could come upon an undiscovered moon or Kuiper Belt Object and they would have to alter course, the biggest issue is tiny debris which may be coming from impacts on the smaller moons.

“We could have 100 moons the size of P4 and they would not be a significant hazard,” Stern said via email. “The hazard is from ejecta coming off these satellites when they are cratered, because the ejecta escapes their feeble gravity and gets into orbit around Pluto.”

At a press conference at the American Astronomical Society’s Division for Planetary Sciences meeting, Stern said that with all the debris in the Kuiper Belt, objects are definitely getting impacted. “If hits occur on Pluto and Charon, they have enough gravity that ejecta just flies across the planet and creates secondary craters. But the ejecta on smaller moons puts shards and debris into the Pluto system.”

Stern said the ejecta speeds from these moons would be comparable to orbital speeds. That means the debris can orbit at any inclination, and there could be a cloud of debris around the system, creating a hazard for the spacecraft.

This worries Stern and his team.

“My spacecraft is going very fast and even a strike from something as small as a BB would be fatal,” he said. “There’s almost no place the spacecraft could get hit and it would be OK.”

Stern said current knowledge of the density of debris of the system can’t prove the spacecraft won’t get hit, and they won’t be able to find out more until they get closer.

“We’re going somewhere new and have no direct evidence of debris that could pose an impact hazard,” he said. “We don’t know what we are going to find and we might have to change our course.”

Stern and his team are looking at some alternative plans, and developing them now is crucial.

“When we plan an encounter for a mission like this, it literally takes tens of thousands of man-hours by experts to put that sequence together and test it,” he said. “We have to plan them now in order to complete that planning. We can’t complete them in the last couple of months or weeks.”

The plans being considered are called SHBOT: Safe Haven Bail Out Trajectory. They currently have nine different possible trajectories, depending on what they find as they get closer.

Screenshot from Stern’s presentation, depicting the nine SHBOT trajectories.

The team is also using every available tool — including sophisticated computer simulations of the stability of debris orbiting Pluto, giant ground-based telescopes, stellar occultation probes of the Pluto system, and even the Hubble Space Telescope — to search for debris in orbit.

Stern told Universe Today that they use the cameras on New Horizons itself every summer when they “wake up” the spacecraft. “LORRI (Long Range Reconnaissance Imager) has already seen Pluto for about 6 years!” he said, “But we won’t pass HST resolution till we’re about 10 weeks out, in April 2015. That’s when we turn on the heavy effort to look for more moons, rings, etc.”

They are looking at the pluses and minuses for each of the plans so they can be tested and be just as “bullet-proof” as the original, nominal flight plan.

In addition to saving the spacecraft, these alternative trajectories also need to preserve the science mission as much as possible. Most of the alternate courses bring the spacecraft farther away from the Pluto system, but one actually brings it closer to Charon, as the path there may be clearer there because of Charon’s gravity and clearing effect.

The spacecraft will start science observations in January 2015, with closest approach to the system currently set for on July 14, 2015 (“Bastille Day,” Stern said, “when we storm the gates of the Pluto system!”)

During the final 50 days of approach, when the spacecraft is taking pictures and sending them back to Earth to be analyzed, the team may discover something and have to fire the spacecraft engines, putting them on one of the SHBOT trajectories. But the last opportunity to actually change course is 10 days before encounter.

“After that we are in too close and we would run out of fuel and not complete the maneuver,” Stern said.

So, while the Mars Science Laboratory team had “Seven minutes of terror” during the perilous landing on Mars, Stern said they have something similar. “We don’t have seven minutes of terror; we have seven weeks of suspense.”

September 26, 2012April 26, 2016 by Jason Major

Researchers Present the Sharpest Image of Pluto Ever Taken from Earth

A “speckle image” reconstruction of Pluto and its largest moon, Charon (Gemini Observatory/NSF/NASA/AURA)

Real planet, dwarf planet, KBO, who cares? What matters here is that astronomers have created the sharpest image of Pluto ever made with ground-based observations — and developed a new way to verify potential Earth-like exoplanets at the same time.

Here’s how they did it:

After taking a series of quick “snapshots” of Pluto and Charon using a recently-developed camera called the Differential Speckle Survey Instrument (DSSI), which was mounted on the Gemini Observatory’s 8-meter telescope in Hawaii, researchers combined them into a single image while canceling out the noise caused by turbulence and optical aberrations. This “speckle imaging” technique resulted in an incredibly clear, crisp image of the distant pair of worlds — especially considering that 1. it was made with images taken from the ground, 2. Pluto is small, and 3. Pluto is very, very far away.

Read: Why Pluto is No Longer a Planet

Less than 3/4 the diameter of our Moon, Pluto (and Charon, which is about half that size) are currently circling each other about 3 billion miles from Earth — 32.245 AU to be exact. That’s a long way off, and there’s still much more that we don’t know than we do about the dwarf planet’s system. New Horizons will fill in a lot of the blanks when it passes close by Pluto in July 2015, and images like this can be a big help to mission scientists who want to make sure the spacecraft is on a safe path.

“The Pluto-Charon result is of timely interest to those of us wanting to understand the orbital dynamics of this pair for the 2015 encounter by NASA’s New Horizons spacecraft,” said Steve Howell of the NASA Ames Research Center, who led the Gemini imaging study.

See images of Pluto taken by Hubble here.

In addition, the high resolution achievable through the team’s speckle imaging technique may also be used to confirm the presence of exoplanet candidates discovered by Kepler. With an estimated 3- to 4-magnitude increase in imaging sensitivity, astronomers may be able to use it to pick out the optical light reflected by a distant Earth-like world around another star.

Speckle imaging has been used previously to identify binary star systems, and with the comparative ability to “separate a pair of automobile headlights in Providence, RI, from San Francisco, CA” there’s a good chance that it can help separate an exoplanet from the glare of its star as well.

The research was funded in part by the National Science Foundation and NASA’s Kepler discovery mission, and will be published in the journal Publications of the Astronomical Society of the Pacific in October 2012. Read more here.

Main image: the first speckle reconstructed image for Pluto and Charon from which astronomers obtained not only the separation and position angle for Charon, but also the diameters of the two bodies. North is up, east is to the left, and the image section shown is 1.39 arcseconds across. Resolution of the image is about 20 milliarcseconds rms. Credit: Gemini Observatory/NSF/NASA/AURA. Inset: the Gemini North telescope on the summit of Mauna Kea. (Gemini Observatory)

August 30, 2012April 26, 2016 by Jason Major

What Has the Kuiper Belt Taught Us About The Solar System?

Over 4 billion miles (6.7 billion km) from the Sun, the Kuiper Belt is a vast zone of frozen worlds we still know very little about. Image: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI)

Today marks the 20th anniversary of the discovery of the first Kuiper Belt Object, 1992QB1. KBOs are distant and mostly tiny worlds made up of ice and rock that orbit the Sun at incredible distances, yet are still very much members of our Solar System. Since 1992 over 1,300 KBOs have been found, and with NASA’s New Horizons spacecraft speeding along to its July 2015 rendezvous with Pluto and Charon (which one could argue are technically the first KBOs ever found) and then onwards into the Belt, we will soon know much more about these far-flung denizens of deep space.

But how has the discovery of the Kuiper Belt — first proposed by Gerard Kuiper in 1951 (and in a fashion even earlier by Kenneth Edgeworth) — impacted our current understanding of the Solar System? New Horizons Principal Investigator Alan Stern from the Southwest Research Institute recently discussed this on his mission blog, “The PI’s Perspective.”

First, Stern lists some of the surprisingly diverse physical aspects of KBOs that have been discovered so far:

Some are red and some are gray;
The surfaces of some are covered in water ice, but others (like Pluto) have exotic volatile ices like methane and nitrogen;
Many have moons, though none with more known moons than Pluto;
Some are highly reflective (like Pluto), others have much darker surfaces;
Some have much lower densities than Pluto, meaning they are primarily made of ice. Pluto’s density is so high that we know its interior is about 70% rock in its interior; a few known KBOs are more dense than Pluto, and even rockier!

But although these features are fascinating in themselves, just begging for further exploration, Stern notes that there are three very important lessons that the Kuiper Belt has taught us about the Solar System:

1. Our planetary system is much larger than we had ever thought.

“In fact, we were largely unaware of the Kuiper Belt — the largest structure in our solar system — until it was discovered 20 years ago,” Stern writes. “It’s akin to not having maps of the Earth that included the Pacific Ocean as recently as 1992!”

2. Planetary locations and orbits can change over time.

“This even creates whole flocks of migration of planets in some cases. We have firm evidence that many KBOs (including some large ones like Pluto), were born much closer to the Sun, in the region where the giant planets now orbit.”

3. Our solar system, and likely others as well, was very good at making small planets.

“Today we know of more than a dozen dwarf planets in the solar system, and those dwarfs already outnumber the number of gas giants and terrestrial planets combined. But it is estimated that the ultimate number of dwarf planets we will discover in the Kuiper Belt and beyond may well exceed 10,000. Who knew?”

And with a little jab at the whole Pluto-isn’t-a-planet topic, Stern asks: “And which class of planet is the misfit now?”

Read: Was Pluto Ever REALLY a Planet?

The discovery of the Kuiper Belt has shown us that our solar system — and very likely planetary systems across the galaxy, even the Universe — aren’t neat and tidy things that can be easily summed up with grade-school models or chalkboard diagrams. Instead they are incredibly diverse and dynamic, continually evolving and consisting of countless, varied worlds spanning enormous distances… yet still connected through the ever-present effects of gravity (not to mention the occasional-yet-unavoidable collision.)

“What an amazing set of paradigm shifts in our knowledge the Kuiper Belt has brought so far. Our quaint 1990s and earlier view of the solar system missed its largest structure!”

– Alan Stern, New Horizons Principal Investigator

Read more about the New Horizons mission here.

The first KBO identified, 1992 QB1 (European Southern Observatory)

July 11, 2012December 23, 2015 by Jason Major

Fifth Moon Found Around Pluto

This just in! Astronomers working with the Hubble Space Telescope have spotted a new moon around distant Pluto, bringing the known count up to 5. The image above was released by NASA just minutes ago, showing the Pluto system with its newest member, P5.

This news comes just a couple of weeks shy of the one-year anniversary of the announcement of Pluto’s 4th known moon, still currently named “P4”.

The news was shared this morning by an undoubtedly excited Alan Stern of the Southwest Research Institute (SwRI) on Twitter.

Astronomers estimate P5 to be between 6 and 15 miles (9.6 to 24 km) in diameter. It orbits Pluto in the same plane as the other moons — Charon, Nix, Hydra and P4.

“The moons form a series of neatly nested orbits, a bit like Russian dolls,” said team lead Mark Showalter of the SETI Institute.

A mini-abstract of an upcoming paper lists image sets acquired on 5 separate occasions in June and July. According to the abstract, P5 is 4% as bright as Nix and 50% as bright as P4.

The satellite’s mean magnitude is V = 27.0 +/- 0.3, making it 4 percent as bright as Pluto II (Nix) and half as bright as S/2011 (134340) 1. The diameter depends on the assumed geometric albedo: 10 km if p_v = 0.35, or 25 km if p_v =0.04. The motion is consistent with a body traveling on a near-circular orbit coplanar with the other satellites. The inferred mean motion is 17.8 +/- 0.1 degrees per day (P = 20.2 +/- 0.1 days), and the projected radial distance from Pluto is 42000 +/- 2000 km, placing P5 interior to Pluto II (Nix) and close to the 1:3 mean motion resonance with Pluto I (Charon).

The new detection will help scientists navigate NASA’s New Horizons spacecraft through the Pluto system in 2015, when it makes an historic and long-awaited high-speed flyby of the distant world.

See the news release from NASA here.

(H/T to Ray Sanders at DearAstronomer.com)

Top image: NASA, ESA and M. Showalter (SETI Institute)

May 31, 2012December 23, 2015 by Jason Major

Was Pluto Ever REALLY a Planet?

Ever since the infamous 2006 reclassification of Pluto off the list of “official” planets (which had a rather incendiary effect on many of the distant world’s Earthly fans) the term “planet” has been seen by some as a variable one, difficult to define and apparently able to be given and taken away. But was Pluto ever really deserving of the title to begin with?

This fun info-animation by C.G.P. Grey suggests that it wasn’t, and offers a compelling explanation why.

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Grey writes on his blog:

“To my constant surprise the issue of Pluto’s planetary status — which I think should be a dry technical issue — really gets people riled. But it’s also been my experience that the people who most want Pluto to be a planet know the least about it and the history of its discovery. So, I hope that this video can help correct that a little bit.”

We still love you, Pluto, no matter what you are!

See more of Grey’s excellent animations on YouTube here.

April 30, 2012December 23, 2015 by Jason Major

OMG Space

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“You may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.” – Douglas Adams

Standard classroom models and textbook illustrations of the Solar System, regardless of how pretty they are, all share one thing in common: they’re wrong. Ok, maybe not wrong, but definitely inaccurate… especially in regards to scale. And understandably so, as it’s nearly impossible to portray in a convenient manner the sheer amount of space there is between the planets and their relative sizes. Even if a model manages to show one or the other in a straightforward, linear fashion, it usually doesn’t show both.

This one does.

OMG Space is a web page made by Margot Trudell as graphic design thesis project at Toronto’s OCAD University. Displayed on the Visual.ly portfolio site, Margot’s expansive infographic shows the Sun, planets and some minor bodies to scale, both in terms of relative size and distance. By clicking on a planet’s name at the bottom of the page you’ll be whisked away toward it, giving a sense of how very far it really is between the many worlds that make up our own little Solar System.

And if that’s not enough, Margot has included a descriptive chart for each world that gives basic information on distance from the Sun, orbital period and moon count as well as details on visiting exploration missions — past, present and planned. These can be accessed by clicking on the respective worlds once you arrive.

pluto-test — Each planet has an infographic associated with it, showing physical characteristics and exploration timelines. (M. Trudell)

“I created the infographics first and as I worked on them decided they needed more context, and the idea of creating a to scale version of our solar system came to mind,” Margot told Universe Today. “The project was initially intended to be all print, but knowing the real scale of our solar system I eventually came up with the idea of using the infiniteness of the web to my advantage.”

If you watch the scroll bar on the right side of the page (and I do suggest resizing the page to fill your screen as much as possible) you’ll also get a sense of how much space you’re traversing as you zip between worlds. And that’s just taking into consideration the average distances between each planet at opposition. In reality, they’re never lined up in a row like that!

If you’re so inclined you can also scroll up and down manually… if only to see how long it takes you to not get anywhere.

“My favourite thing to do on OMG Space’s website is go to Earth and then click on the link to the Moon,” Margot said. “The small distance you move yet the big gap you see… it gives you a whole new perspective on how far people traveled to get to the moon and back, and it shows how far the moon really is from Earth (I feel that it’s always portrayed as being almost right beside us) and makes you consider how powerful those rockets must have been to get us that far.

“It gives you a bit of that ‘OMG’ feeling that the project is named for.”

Yes, OMG indeed.

Infographics by Margot Trudell. See more of Margot’s work here.