Tag: Dwarf Planets

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One year later, New Horizons revisits Pluto flyby

160714-pluto6
Composite image shows enhanced-color views of Charon and Pluto. (Credit: NASA / JHUAPL / SwRI)

One year ago today, NASA’s New Horizons probe whizzed past Pluto and opened up a new frontier for planetary science – and to mark the occasion, the mission team is looking back at its greatest hits and looking ahead to a landing.

“It’s strange to think that only a year ago, we still had no real idea of what the Pluto system was like,” project scientist Hal Weaver, who’s based at the Johns Hopkins University Applied Physics Laboratory, said in a news release celebrating the anniversary. “But it didn’t take long for us to realize Pluto was something special, and like nothing we ever could have expected.”

After more than nine years of cruising through interplanetary space, the piano-sized New Horizons spacecraft flew by Pluto and its moons at a speed of more than 30,000 mph on July 14, 2015, capturing readings as it went. Since then, the probe has been transmitting gigabytes’ worth of data back to Earth at a slow but steady rate.

The pictures have been unprecedented, providing the first close look at icy worlds that whirl more than 3 billion miles from the sun, in a region known as the Kuiper Belt. They’ve even inspired a set of postage stamps.

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Astronomers spot an icy world beyond Pluto

The golden ellipse indicates the orbit of the newly confirmed object 2015 RR245. Click on the image for a larger version. (Credit: Alex Parker / OSSOS Team)
The golden ellipse indicates the orbit of the newly confirmed object 2015 RR245. Click on the image for a larger version. (Credit: Alex Parker / OSSOS Team)

Astronomers have found an icy world that ranges far beyond the orbit of Neptune and may well rank as a dwarf planet alongside Pluto.

The newly detected object, designated 2015 RR245, is thought to be less than a third the width of Pluto (435 miles vs. 1,474 miles), but its orbit is more eccentric. Its distance from the sun ranges from about 34 to more than 120 astronomical units, where each AU equals the distance between Earth and the sun. In comparison, Pluto’s orbit has a range of 30 to 50 AU.

Right now, 2015 RR245 is 80 AU from the sun and closing in, based on observations from the Canada-France-Hawaii Telescope on Hawaii’s big island. It should reach the nearest point in its 733-year orbit in the year 2096.

“The icy worlds beyond Neptune trace how the giant planets formed and then moved out from the sun. They let us piece together the history of our solar system. But almost all of these icy worlds are painfully small and faint: It’s really exciting to find one that’s large and bright enough that we can study it in detail,” Michele Bannister, an astronomer at the University of Victoria in British Columbia, said in a statement.

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This may be the best view of Pluto we ever see

Image: Pluto surface
Craters and linear features are scattered across Pluto’s terrain in this high-resolution view from NASA’s New Horizons probe. (Credit: NASA / JHUAPL / SwRI)

Almost a year after NASA’s New Horizons probe flew past Pluto, the team behind the mission has put together a long mosaic strip that includes all of the highest-resolution images.

“This new image product is just magnetic,” Alan Stern, a planetary scientist from Southwest Research Institute who serves as New Horizons’ principal investigator, said today in a NASA news release. “It makes me want to go back on another mission to Pluto and get high-resolution images like these across the entire surface.”

The view starts up at the edge of Pluto’s disk and runs hundreds of miles, down to nearly the terminator line between Plutonian day and night. The width of the strip ranges from 45 to 55 miles, depending on the perspective. Peak resolution is about 260 feet per pixel.

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2007 OR10 deserves a better name

Image: Dwarf planets compared
An illustration lines up the solar system’s four largest dwarf planets, with 2007 OR10 in the middle of the pack. (Credit: Andras Pal / Konkoly Observatory, Ivan Eder / Hungarian Astronomical Association, NASA / JHUAPL / SwRI)

Observations made by NASA’s Kepler space telescope suggest that the icy world known as 2007 OR10 is bigger than astronomers thought –and that’s adding to the pressure to give the probable dwarf planet an official name, nine years after its discovery.

Some of the suggestions pick up on the recent controversy over a British ship-naming contest in which Boaty McBoatface emerged as the overwhelming favorite. So how about Dwarfplanety McDwarfplanetface, or Plutoid McPlutoface?

The cause of all this mirth is a research paper in the Astronomical Journal that provides a new size estimate for 2007 OR10, which lies far out in the Kuiper Belt, the broad ring of icy material just beyond Neptune. The object traces an eccentric orbit that takes 547.51 Earth years to complete, and ranges as far out as 66.9 times Earth’s distance from the sun (6.2 billion miles).

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Hubble spots dwarf planet Makemake’s moon

Image: Makemake and MK 2
An artist’s conception shows the distant dwarf planet Makemake with its dark moon, MK 2, lurking to the right. (Credit: NASA / ESA / A. Parker / SwRI)

Chalk up another moon for the dwarf planets: Astronomers have sifted through imagery from the Hubble Space Telescope to find a tiny satellite circling Makemake.

Makemake (pronounced Mah-kay-mah-kay, like the Rapa Nui deity after which it’s named) is one of the five dwarf planets recognized by the International Astronomical Union, along with Pluto, Eris, Haumea and Ceres. It’s more than 50 times farther away from the sun than Earth is, which translates to a distance of 4.8 billion miles.

With a diameter of 870 miles, Makemake is the third-largest known solar system object beyond the orbit of Neptune, in a wide ring of icy material called the Kuiper Belt. (Planet Nine, a.k.a. Planet X, would change the order if it exists, but it hasn’t yet been found.)

Like Eris, the dwarf planet that stirred up all the fuss over Pluto’s planetary status, Makemake was discovered in 2005 by a team led by Caltech astronomer Mike Brown. Like Pluto, Makemake is thought to be covered in frozen methane.

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Ceres’ mystery spots get their close-up

Image: Occator Crater
The bright central spots near the center of Occator Crater are shown in enhanced color in this view from NASA’s Dawn spacecraft. Such views can be used to highlight subtle color differences on Ceres’ surface. The view combines high-resolution images of Occator from February with lower-resolution color data from September. (Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / PSI / LPI)

The scientists behind NASA’s Dawn mission today showed off their latest, greatest pictures of the dwarf planet Ceres, including close-up views of curious bright spots on the surface.

The car-sized Dawn spacecraft has been circling Ceres, the biggest mini-world in the solar system’s asteroid belt, for just more than a year. In Dawn’s distant views, the bright spots looked like alien headlights. The latest images, captured from a height of just 240 miles, reveal that the brightest spot is a fractured dome sticking up from 57-mile-wide Occator Crater.

Other bright areas appear to be highly reflective deposits, crisscrossed by linear features and fractures.

Dawn’s scientists discussed their latest data today at the Lunar and Planetary Science Conference in The Woodlands, Texas.

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Map reveals more water ice on Pluto

Image: Pluto water map
This false-color infrared image from NASA’s New Horizons spacecraft shows water ice concentrations on Pluto. The left image is the result of an initial analysis, and the right image has been reprocessed to account for mixtures with other types of ice. (Credit: NASA / JHUAPL / SwRI)

A color-coded map from NASA’s New Horizons mission shows where Pluto’s frozen water is concentrated, just in case we need to fill up our tanks on the way toAlpha Centauri or Planet Nine.

Water ice turns out to be more widespread on the dwarf planet than previously thought, the mission’s researchers reported today. They came to that conclusion after some sophisticated analysis of infrared imagery captured during the New Horizons spacecraft’s flyby last July 14.

Soon after the flyby, the mission team concluded that Pluto possessed mountains of water ice rising as high as 11,000 feet above the icy world’s surface. That conclusion was confirmed in follow-up studies based on the infrared data from the piano-sized probe’s Ralph/LEISA instrument.

LEISA’s survey mapped concentrations of water ice, but scientists figured out that the spectral readings could be thrown off if the frozen water was mixed in with frozen methane. When they modeled the contributions from other types of ice on Pluto’s surface, the resulting map showed wider stretches where water ice should be present.

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Dawn sheds more light on Ceres’ bright spots

Image: Kupalo Crater on Ceres
This image of Ceres’ Kupalo Crater was captured by NASA’s Dawn spacecraft from a height of about 240 miles on Dec. 21. (Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA)

For years, scientists puzzled over the bright spots that shine like alien headlights from the surface of Ceres, a dwarf planet in the main asteroid belt. Scientists are leaning toward identifying them as salt deposits, and now there’s a new line of evidence that could help tell the tale definitively.

The evidence takes the form of bright deposits in Kupalo Crater, one of the freshest craters spotted on Ceres. In this case, just a little bit of bright material can be seen on on the crater’s floor. But lots of the stuff is tumbling down from the crater’s rim.

The material shows up clearly in an image captured by NASA’s Dawn spacecraft. Dawn has been circling Ceres since last March, but last month it descended to a 240-mile orbit for up-close imaging. The newly released picture of Kupalo Crater was taken Dec. 21.

“This crater and its recently formed deposits will be a prime target of study for the team as Dawn continues to explore Ceres in its final mapping phase,” Paul Schenk, a Dawn science team member at the Lunar and Planetary Institute in Houston, said Tuesday in a NASA news release.

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NASA’s mission to Pluto shares its latest X-Files

Image: Pluto's Sputnik Planum
This image from NASA’s New Horizons spacecraft shows patterns in the nitrogen glaciers of an area nicknamed Sputnik Planum – including an “X” to the right and below the image’s center. The darker patch at the center of the image is probably a dirty block of water ice “floating” in the denser nitrogen. (Credit: NASA / JHUAPL / SwRI)

If “X-Files” are defined as data about weird and alien phenomena, NASA’s New Horizons mission to Pluto has X-Files galore. And this week, the mission’s science team shared an X-File with an actual X on it.

The timing of Thursday’s image release couldn’t be much better, coming just a couple of weeks before “The X-Files” (the TV show, that is) returns to Fox for a six-episode run. But this is no publicity stunt; rather, it illustrates how weird geology can get on a world that features glaciers of frozen nitrogen.

The semi-solid nitrogen in a region informally known as Sputnik Planum slowly burbles up and down, due to thermal convection. When blobs of nitrogen rise up and press against each other, patterns of lines mark the boundaries between the blobs. When the blobs subside, the lines disappear.

“This part of Pluto is acting like a lava lamp, if you can imagine a lava lamp as wide as, and even deeper than, the Hudson Bay,” William McKinnon, a researcher from Washington University in St. Louis who’s the deputy lead of the New Horizons geology, geophysics and imaging team, said in a NASA feature.

The results can be seen in a mosaic of Sputnik Planum imagery.

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See Ceres as you’ve never seen it before

Image: Ceres
This Dec. 10 image of Ceres shows the area around a crater chain called Gerber Catena,. NASA’s Dawn spacecraft was flying about 240 miles above Ceres when the picture was taken. (Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA).

Earlier this month we started seeing some of the closest views yet of Pluto, and now it’s time for close-ups from a closer dwarf planet: Ceres.

NASA’s Dawn orbiter has begun delivering pictures of the solar system’s biggest asteroid and smallest known dwarf planet as seen from its closest vantage point, just 240 miles (385 kilometers) above the surface. That’s roughly how high the International Space Station flies above Earth.

One of the more intriguing views released today shows the area around a crater chain called Gerber Catena. Get out your red-blue glasses, and you can easily spot a trough running through a 3-D view of the terrain.

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