Pluto – Just Look at the Detail!

We did it! At 7:49 a.m. EDT today New Horizons made history when it zoomed within 7,800 miles of Pluto, the most remote object ever visited in the Solar System. I thought you’d like to see our best view yet of Pluto in this last and sharpest image taken before closest approach. The level of detail is fantastic.

Universe Today’s Ken Kremer is on the scene at mission control, and we’ll have much more news and analysis for you later  today.  For now, here’s a taste.

Members of NASA's New Horizons team react to seeing the latest image of Pluto. Credit: NASA
Members of NASA’s New Horizons team react to seeing the latest image of Pluto. Credit: NASA


Pluto encounter July 14th 11:00-12:00 UTC (6:00am CDT) by Tom Ruen

Efrain Morales created this fine document of Pluto seen from New Horizons and photographed at nearly
Efrain Morales created this fine document of the Pluto encounter by combining the recent New Horizons photo with images taken through his telescope about 6 1/2 hours before closest approach. Images taken on July 10 and 11 show Pluto’s slow crawl across the starfield. Credit: Efrain Morales
This graphic presents a view of Pluto and Charon as they would appear if placed slightly above Earth's surface and viewed from a great distance.  Recent measurements obtained by New Horizons indicate that Pluto has a diameter of 2370 km, 18.5% that of Earth's, while Charon has a diameter of 1208 km, 9.5% that of Earth's. Credit: NASA/JHUAPL/SWRI
To give you a better idea of how small New Horizons’ targets are, this graphic shows Pluto and Charon as they would appear if placed slightly above Earth’s surface and viewed from a great distance. Recent measurements obtained by New Horizons indicate that Pluto has a diameter of 1,473 miles (2370 km, making it the largest known Kuiper Belt object, while Charon has a diameter of 751 miles (1208 km). Credit: NASA/JHUAPL/SWRI

Pluto has a very complex surface. The fact that large areas show few craters – as compared to say, Ceres or Vesta – shows that there have relatively recent changes there. Maybe very recent. Alan Stern, principal investigator for the mission, was asked by a report at this morning’s press conference if it snows on Pluto. His answer: “It sure looks like it.”

Mission principal investigator has reason to smile this morning during the press conference. So far, New Horizons is doing well. Credit: NASA-TV
Mission principal investigator has reason to smile this morning during the press conference. So far, New Horizons is doing well. Credit: NASA-TV

Stern is also confident the spacecraft survived closest approach without getting bulleted by dust. We should know tonight when it “phones home” around 9 p.m. EDT.

Even Rosetta couldn't resist a look at Pluto. On July 12, the spacecraft took many images of the distant world and stacked them to create the photos above. Left: The unprocessed image is obscured by dust grains in Comet 67P/C-G’s coma. Middle: Pluto’s background of stars as seen from Rosetta. Right: The processed image shows Pluto as a bright spot within the blue circle. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Even Rosetta couldn’t resist a look at Pluto. On July 12, the spacecraft took many images of the distant world which were stacked to create the photos above. Left: The unprocessed image is obscured by dust grains in Comet 67P/C-G’s coma. Middle: Pluto’s background of stars as seen from Rosetta. Right: The processed image shows Pluto as a bright spot within the blue circle.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

With the Pluto flyby the latest achievement in over 50 years of humankind’s exploration of the Solar System’s wild assortment of moons, planets and comets, see the bounty of our efforts in this wonderful compendium titled From Pluto to the Sun by Jon Keegan, Chris Canipe and Alberto Cervantes.

Pluto’s Time to Shine Just Hours Away – A Guide and Timetable

Countdown to discovery! Not since Voyager 2’s flyby of Neptune in 1989 have we flung a probe into the frozen outskirts of the Solar System. Speeding along at 30,800 miles per hour New Horizons will pierce the Pluto system like a smartly aimed arrow. 

Pluto as seen from New Horizons on July 11, 2015. Credits: NASA/JHUAPL/SWRI
Newest view of Pluto seen from New Horizons on July 11, 2015 shows a world that continues to grow more fascinating and look stranger every day. See annotated version below.
Credits: NASA/JHUAPL/SWRI
On July 11, 2015, New Horizons captured a world that is growing more fascinating by the day. For the first time on Pluto, this view reveals linear features that may be cliffs, as well as a circular feature that could be an impact crater. Rotating into view is the bright heart-shaped feature that will be seen in more detail during New Horizons’ closest approach on July 14. The annotated version includes a diagram indicating Pluto’s north pole, equator, and central meridian. Credits: NASA/JHUAPL/SWRI
For the first time on Pluto, this view reveals linear features that may be cliffs, as well as a circular feature that could be an impact crater. Rotating into view is the bright heart-shaped feature that will be seen in more detail during New Horizons’ closest approach on July 14. The annotated version includes a diagram indicating Pluto’s north pole, equator, and central meridian.
Credits: NASA/JHUAPL/SWRI

Edging within 7,800 miles of its surface at 7:49 a.m. EDT, the spacecraft’s long-range telescopic camera will resolve features as small as 230 feet (70 meters). Fourteen minutes later, it will zip within 17,930 miles of Charon as well as image Pluto’s four smaller satellites — Hydra, Styx, Nix and Kerberos.

This image shows New Horizons' current position (3 p.m. EDT July 12) along its planned Pluto flyby trajectory. The green segment of the line shows where New Horizons has traveled; the red indicates the spacecraft's future path. The Pluto is tilted up like a target because the planet's axis is tipped 123° to the plane of its orbit. Credit: NASA/JHUAPL/SWRI
This image shows New Horizons’ current position (3 p.m. EDT July 12) along its planned Pluto flyby trajectory. The green segment of the line shows where New Horizons has traveled; the red indicates the spacecraft’s future path. The Pluto system is tilted on end because the planet’s axis is tipped 123° to the plane of its orbit. Credit: NASA/JHUAPL/SWRI

After zooming past, the craft will turn to photograph Pluto eclipsing the Sun as it looks for the faint glow of rings or dust sheets illuminated by backlight. At the same time, sunlight reflecting off Charon will faintly illuminate Pluto’s backside. What could be more romantic than Charonshine?

Six other science instruments will build thermal maps of the Pluto-Charon pair, measure the composition of the surface and atmosphere and observe Pluto’s interaction with the solar wind. All of this will happen autopilot. It has to. There’s just no time to send a change instructions because of the nearly 9-hour lag in round-trip communications between Earth and probe.

Instruments New Horizons will use to characterize Pluto are REX (atmospheric composition and temperature; PEPSSI (composition of plasma escaping Pluto's atmosphere); SWAP (solar wind); LORRI (close up camera for mapping, geological data); Star Dust Counter (student experiment measuring space dust during the voyage); Ralph (visible and IR imager/spectrometer for surface composition and thermal maps and Alice (composition of atmosphere and search for atmosphere around Charon). Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Instruments New Horizons will use to characterize Pluto are REX (atmospheric composition and temperature); PEPSSI (composition of plasma escaping Pluto’s atmosphere); SWAP (solar wind studies); LORRI (close up camera for mapping, geological data); Star Dust Counter (student experiment measuring space dust during the voyage); Ralph (visible and IR imager/spectrometer for surface composition and thermal maps) and Alice (composition of atmosphere and search for atmosphere around Charon). Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Want to go along for the ride? Download and install NASA’s interactive app Eyes on Pluto and then click the launch button on the website. You’ll be shown several options including a live view and preview. Click preview and sit back to watch the next few days of the mission unfold before your eyes.

American astronomer Clyde Tombaugh discovered Pluto in 1903 from Lowell Observatory. Tombaugh died in 1997, but an ounce of his ashes, affixed to the spacecraft in a 2-inch aluminum container. "Interned herein are remains of American Clyde W. Tombaugh, discoverer of Pluto and the solar system's 'third zone.' Adelle and Muron's boy, Patricia's husband, Annette and Alden's father, astronomer, teacher, punster, and friend: Clyde Tombaugh (1906-1997)"
American astronomer Clyde Tombaugh discovered Pluto in 1930 from Lowell Observatory. Tombaugh died in 1997, but an ounce of his ashes, affixed to the spacecraft in a 2-inch aluminum container. “Interned herein are remains of American Clyde W. Tombaugh, discoverer of Pluto and the solar system’s ‘third zone.’ Adelle and Muron’s boy, Patricia’s husband, Annette and Alden’s father, astronomer, teacher, punster, and friend: Clyde Tombaugh (1906-1997)”

Like me, you’ve probably wondered how daylight on Pluto compares to that on Earth. From 3 billion miles away, the Sun’s too small to see as a disk with the naked eye but still wildly bright. With NASA’s Pluto Time, select your city on an interactive map and get the time of day when the two are equal. For my city, daylight on Pluto equals the gentle light of early evening twilight six minutes after sunset. An ideal time for walking, but step lightly. In Pluto’s gentle gravity, you only weigh 1/15 as much as on Earth.

Pluto and its cohorts in the icy-asteroid-rich Kuiper Belt beyond the orbit of Neptune. Credit: NASA
Pluto and its inclined orbit are highlighted among the hundreds of thousands of icy asteroids in the Kuiper Belt beyond Neptune. Credit: NASA

New Horizons is the first mission to the Kuiper Belt, a gigantic zone of icy bodies and mysterious small objects orbiting beyond Neptune. This region also is known as the “third” zone of our solar system, beyond the inner rocky planets and outer gas giants. Pluto is its most famous member, though not necessarily the largest. Eris, first observed in 2003, is nearly identical in size. It’s estimated there are hundreds of thousands of icy asteroids larger than 61 miles (100 km) across along with a trillion comets in the Belt, which begins at 30 a.u. (30 times Earth’s distance from the Sun) and reaches to 55 a.u.

During its fleeting flyby, New Horizons will slice across the Pluto system, turning this way and that to photograph and gather data on everything it can. Crucial occultations are shown that will be used to determine the structure and composition of Pluto’s (and possibly Charon’s) atmosphere. Credit: NASA with additions by the author
During its fleeting flyby, New Horizons will slice across the Pluto system, turning this way and that to photograph and gather data on everything it can. Crucial occultations are shown that will be used to determine the structure and composition of Pluto’s (and possibly Charon’s) atmosphere. Sunlight reflected from Charon will also faintly illuminate Pluto’s backside. Credit: NASA with additions by the author

Below you’ll find a schedule of events in Eastern Time. (Subtract one hour for Central, 2 hours for Mountain and 3 hours for Pacific). Keep in mind the probe will be busy shooting photos and gathering data during the flyby, so we’ll have to wait until Wednesday July 15 to see the the detailed close ups of Pluto and its moons. Even then, New Horizons’ recorders will be so jammed with data and images, it’ll take months to beam it all back to Earth.

Chasms, craters, and a dark north polar region are revealed in this image of Pluto’s largest moon Charon taken by New Horizons on July 11, 2015. The annotated version includes a diagram showing Charon’s north pole, equator, and central meridian, with the features highlighted. Credits: NASA/JHUAPL/SWRI
A new photo of Charon, too! Chasms, craters, and a dark north polar region are revealed in this image of Pluto’s largest moon taken by New Horizons on July 11, 2015. The annotated version includes a diagram showing Charon’s north pole, equator, and central meridian, with the features highlighted. The prominent crater is about 60 miles (96 km) across; the chasms appear to be geological faults. 
Credits: NASA/JHUAPL/SWRI

Fasten your seat belts — we’re in for an exciting ride.

We’ll be reporting on results and sharing photos from the flyby here at Universe Today, but you’ll also want to check out NASA’s live coverage on NASA TV, its website and social media.

Monday, July 13
10:30 a.m. to noon – Media briefing on mission status and what to expect broadcast live on NASA TV

Tuesday, July 14
7:30 to 8 a.m. – Arrival at Pluto! Countdown program on NASA TV

At approximately 7:49 a.m., New Horizons is scheduled to be as close as the spacecraft will get to Pluto, approximately 7,800 miles (12,500 km) above the surface, after a journey of more than 9 years and 3 billion miles. For much of the day, New Horizons will be out of communication with mission control as it gathers data about Pluto and its moons.

The moment of closest approach will be marked during a live NASA TV broadcast that includes a countdown and discussion of what’s expected next as New Horizons makes its way past Pluto and potentially dangerous debris.

8 to 9 a.m. – Media briefing, image release on NASA TV

Wednesday, July 15

3 to 4 p.m. – Media Briefing: Seeing Pluto in a New Light; live on NASA TV and release of close-up images of Pluto’s surface and moons, along with initial science team reactions.

We’ll have the latest Pluto photos for you, but you can also check these excellent sites:

* Long Range Reconnaissance Imager (LORRI) archive
Pluto Photojournal
* New Horizons science photo gallery

Need more Pluto? Spend a few minutes watching this excellent New York Times mission documentary.

Scientists Captivated By Pluto’s Emerging Geological Wonders

Bit by the Pluto bug? Day by day, new images appear showing an ever clearer view of a world we inexplicably love. Call it a dwarf planet. Call it a planet. It’s the unknown, and we can’t help but be drawn there.

Pluto made history when it was discovered in 1930. In 2015, it’s doing it all over again. Check out the new geology peeping into view.I’m reminded of the early explorers who shoved off in wooden ships in search of land across the water. After a long and often perilous journey, the mists would finally clear and the dark outline of land take form in the distance. It’s been 9 1/2 years since our collective Pluto voyage began. Yeah, we’re almost there.

Science team members react to the latest image of Pluto at the Johns Hopkins University Applied Physics Lab on July 10, 2015. Left to right: Cathy Olkin, Jason Cook, Alan Stern, Will Grundy, Casey Lisse, and Carly Howett. Credit: Michael Soluri
Science team members react to the latest image of Pluto at the Johns Hopkins University Applied Physics Lab on July 10, 2015. Left to right: Cathy Olkin, Jason Cook, Alan Stern, Will Grundy, Casey Lisse, and Carly Howett.
Credit: Michael Soluri

Today’s image release clearly shows a world growing more geologically diverse by the day.

“We’re close enough now that we’re just starting to see Pluto’s geology,” said New Horizons program scientist Curt Niebur, on NASA’s website. Niebur, who’s keenly interested in the gray area just above the whale’s “tail” feature, called it a “unique transition region with a lot of dynamic processes interacting, which makes it of particular scientific interest.”

The non-annotated version of the top photo. The 'whale' lies near the dwarf planet's equator. Pluto's axis is tilted 123° to its orbital plane. Credit: NASA
The non-annotated version of the top photo. The ‘whale’ lies near the dwarf planet’s equator. Pluto’s axis is tilted 123° to its orbital plane. Credit: NASA-JHUAPL-SWRI

Not only that, but the new photo shows an approximately 1,000-mile-long band of swirly terrain crossing the planet from east to northeast, a large, polygonal (roughly hexagonal) feature and new textures within the ‘whale’.

Neptune's largest moon Triton photographed on August 25, 1989 by Voyager 2. Credit: NASA
Neptune’s largest moon Triton photographed on August 25, 1989 by Voyager 2. Triton has a surface of mostly frozen nitrogen, a water ice-rich crust, an icy mantle and rock-metal core. Credit: NASA

Even to a layperson’s eye, Pluto’s terrain  appears very different from that of Ceres or Vesta. In trying to make sense of what we see, Neptune’s moon Triton may be our best Plutonian analog with its frosts, weird cantaloupe terrain and an assortment of dark patches, some produced by icy volcanism.

New Horizons was about 3.7 million miles (6 million kilometers) from Pluto and Charon when it snapped this portrait late on July 8, 2015. Credits: NASA-JHUAPL-SWRI
New Horizons was about 3.7 million miles (6 million kilometers) from Pluto and Charon when it snapped this portrait late on July 8, 2015.
Credits: NASA-JHUAPL-SWRI

Other recent photos include this pretty view of Charon and Triton snapped late on July 8. NASA describes them eloquently as “two icy worlds, spinning around their common center of gravity like a pair of figure skaters clasping hands.” Charon and all of Pluto’s known moons formed from debris released when another planet struck Pluto long ago. New Horizons principal investigator Alan Stern attributes its bland color to its composition — mostly water ice. Pluto in contrast has a mantle of water ice, but it’s coated with methane, nitrogen and carbon dioxide ices and possibly organic compounds, too.

Color photos of Pluto and Charon side by side. The arcs along Pluto's right limb are artifacts but not the white border along the bottom. Could it be frost? Credit:
Color photos of Pluto and Charon side by side. The arcs along Pluto’s right limb are artifacts but not the white border along the bottom. Could it be frost? Credit: NASA-JHUAPL-SWRI

Hold on tight – there’s LOTS more to come!

NASA Loses Contact with New Horizons; Probe Now in Safe Mode

For a nail-biting hour and 20 minutes, NASA lost contact yesterday afternoon July 4 with the New Horizons spacecraft just 9 days before its encounter with Pluto. Communication has since been reestablished and the spacecraft is healthy.

(UPDATE July 6: Great news! The mission will return to normal science operations July 7 – more details below.) 

At 1:54 p.m. EDT, communications suddenly stopped and weren’t reestablished until 3:15 p.m. through NASA’s Deep Space Network. During the time it was out of contact with mission control, the spacecraft’s autonomous autopilot recognized the problem and did what it was programmed to do, switching from the main to the backup computer, according to NASA officials. The autopilot then commanded the backup computer to put New Horizons in “safe mode” — where all non-essential functions are shut down — and reinitiate communications with Earth.

Artist view of New Horizons passing Pluto and three of its moons. The ship is about the size of a grand piano and kept warm in the cold of the outer Solar System by  heat release from the radioactive decay of plutonium within the probe's RTGs (Radioisotope  Thermoelectric Generator). Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Artist view of New Horizons passing Pluto and three of its moons. The ship is about the size of a grand piano and kept warm by heat released from the radioactive decay of plutonium within the probe’s RTG (Radioisotope Thermoelectric Generator). To further retain heat in the frigid cold far from the Sun, it’s insulated with multi-layer blankets. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Success! We’re now back in touch with the spacecraft and engineers are monitoring telemetry to figure out what went wrong.  New Horizons is presently almost 3 billion miles (4.9 billion km) from Earth. Due to the 8.8 hour, round trip communication delay, full recovery is expected to take from one to several days. During that time New Horizons will be unable to collect science data.

If there’s any upside to this, it’s that it happened now instead of 9 days from now. On July 14 at 7:49:57 a.m. EDT  the spacecraft will pass closest to Pluto.

Check back for updates. In the meantime, you can watch a live connection between New Horizons and the Deep Space Network. The probe is labeled NHPC and the dish 63 (first entry).

UPDATE: July 6. NASA announced earlier this morning that has concluded the glitch that caused the New Horizons spacecraft to go into safe mode was not due to a software or hardware fault.

“The underlying cause of the incident was a hard-to-detect timing flaw in the spacecraft command sequence that occurred during an operation to prepare for the close flyby. No similar operations are planned for the remainder of the Pluto encounter,” according to a NASA release.

No primary science will be lost and secondary goals were only slightly compromised. Mission control expects science operations to resume on July 7 and to conduct the entire close flyby sequence as planned.

“In terms of science, it won’t change an A-plus even into an A,” said New Horizons Principal Investigator Alan Stern.

Whew! What a sense of relief. Onward!

Red-faced Pluto Full of Surprises

Hey, Mars, you’ve got company. Looks like there’s a second “red planet” in the Solar System — Pluto. Color images returned from NASA’s New Horizons spacecraft, now just 10 days from its encounter with the dwarf planet, show a distinctly ruddy surface with patchy markings that strongly resemble Mars’ appearance in a small telescope.

Animation of Pluto rotating from photos taken by New Horizons two weeks before the flyby. Credit:
Animation of Pluto’s rotation from photos taken by New Horizons two weeks before the flyby. What are those four nearly parallel dark streaks? Credit: NASA/JHUAPL/SWRI

On Mars, iron oxide or rust colors the planet’s soil, while Pluto’s coloration is likely caused by hydrocarbon molecules called tholins that are formed when cosmic rays and solar ultraviolet light interact with methane in Pluto’s atmosphere and on its surface. Airborne tholins fall out of the atmosphere and coat the surface with a reddish gunk.

Scientists at Johns Hopkins University’s Hörst Laboratory have produced complex chemical compounds called tholins, which may give Pluto its reddish hue. Credits: Chao He, Xinting Yu, Sydney Riemer, and Sarah Hörst, Johns Hopkins University
Scientists at Johns Hopkins University’s Hörst Laboratory have produced complex chemical compounds called tholins, which may give Pluto its reddish hue.
Credits: Chao He, Xinting Yu, Sydney Riemer, and Sarah Hörst, Johns Hopkins University

A particular color or wavelength of UV light called Lyman-alpha is most effective at stimulating the chemical reactions that build hydrocarbons at Pluto. Recent measurements with New Horizons’ Alice instrument reveal the diffuse glow of Lyman-alpha light all around the dwarf planet coming from all directions of space, not just the Sun.

Since one of the main sources of Lyman-alpha light besides the Sun are regions of vigorous star formation in young galaxies, Pluto’s cosmetic rouge may originate in events happening millions of light years away.

Triton's pink too! Montage of Neptune's largest moon, Triton (1,683 miles in diameter) and the planet Neptune showing the moon's sublimating south polar cap (bottom) and enigmatic "cantaloupe terrain". Credit: NASA
Triton’s pink too! Montage of Neptune’s largest moon, Triton (1,683 miles in diameter) and the planet Neptune showing the moon’s sublimating south polar cap (bottom) and enigmatic “cantaloupe terrain”. Photo taken by Voyager 2 in 1989. Credit: NASA

“Pluto’s reddish color has been known for decades, but New Horizons is now allowing us to correlate the color of different places on the surface with their geology and soon, with their compositions,” said New Horizons principal investigator Alan Stern of the Southwest Research Institute, Boulder, Colorado.

Tholins have been found on other bodies in the outer Solar System, including Titan and Triton, the largest moons of Saturn and Neptune, respectively, and made in laboratory experiments that simulate the atmospheres of those bodies.

True color photos showing the two hemispheres of Pluto. At right, you can clearly see the four streaks in a row. New Horizons will approach fly by the hemisphere on the left side.
True color photos showing the two hemispheres of Pluto photographed on June 27, 2015. At left, a large, dark red patch is visible. The four streaks in a row are seen at right. New Horizons will fly by the hemisphere in the left image. Credit:  NASA/JHUAPL/SWRI

As you study the photos and animation, you’ll notice that Pluto’s largest dark spot is redder than the most of the surface; you also can’ help but wonder what’s going on with those four evenly-spaced dark streaks in the equatorial zone. When I first saw them, my reaction was “no way!” They look so neatly lined up I assumed it was an image artifact, but after seeing the rotating movie, maybe not. It’s more likely that low resolution enhances the appearance of alignment.

Dark streaks on Triton formed by deposits from ice or cryovolcanos. Credit: NASA
Dark streaks on Triton deposited downwind from ice or cryovolcanos. Credit: NASA

But what are they? Located as they are on the Charon-facing side of Pluto, they may be related to long-ago tidal stresses induced by each body on the other as they slowly settled into their current tidally-locked embrace or something as current as seasonal change.

Voyager 2 photographed cyrovolcanos at Triton during its 1989 flyby of the Neptune system. Nitrogen geysers and plumes of gas and ice as high as 5 miles (8 km) were seen erupting from active volcanoes, leaving dark streaks on its icy surface.

Images showing the increase in detail from late June through July 1 as New Horizons homes in on Pluto. Credit:
Images showing the increase in detail from late June through July 1 as New Horizons homes in on Pluto. That possible big crater (seen in bottom middle photo) now looks more like a large, dark patch, BUT we still don’t know for sure what it is. Credit: NASA / JHUAPL / SwRI / Björn Jónsson
It's instructive to compare these images based on observations with the Hubble Space Telescope made well before New Horizons's arrival. They appear to record the large dark spot and possible the multiple streaks. Credit: NASA/ESA
It’s instructive to compare these images, based on observations with the Hubble Space Telescope made well before New Horizons’s arrival, with current photos. They appear to record the large dark spot and possibly the multiple streaks. Credit: NASA/ESA

Seasonal heating from the Sun is the most likely cause for Triton’s eruptions; Pluto’s dark streaks may have a similar origin.

Animation of Pluto and Charon from images taken between June 23 and June 29. Credit:
Animation of Pluto and Charon from images taken between June 23 and June 29. Credit: NASA/JHUAPL/SWR
To give you a better picture in your head how big these small bodies are, Pluto and Charon would both fit within the United States with room to spare. Credit: Laboratory for Atmospheric and Space Physics (LASP)
To better picture in your head how big these small bodies really are, Pluto and Charon would both fit within the United States with room to spare. Credit: Laboratory for Atmospheric and Space Physics (LASP)

Today, New Horizons lies just 7.4 million miles (11.9 million km) from its target. Sharpness and detail visible will rapidly improve in just a few days.

“Even at this resolution, Pluto looks like no other world in our Solar System,” said mission scientist Marc Buie of the Southwest Research Institute, Boulder in a recent press release.

Indeed!

Is That a Big Crater on Pluto? Pyramidal Mountain Found on Ceres

You’re probably as eager as I am for new images of Pluto and Ceres as both New Horizons and Dawn push ever closer to their respective little worlds. Recent photos, of which there are only a few, reveal some wild new features including what appears to a large crater on Pluto.

The latest photo of Pluto (lower left) and its largest moon Charon taken on June 29. A large possible crater-like feature is visible at lower right. Charon shows intriguing dark markings. Pluto's diameter is  1,471 miles (700 miles smaller than Earth's Moon); Charon is 750 miles across. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
The latest photo of Pluto (lower left) and its largest moon Charon taken on June 29. A large possible crater-like feature is visible at lower right. Charon shows intriguing dark markings. Pluto’s diameter is 1,471 miles (700 miles smaller than Earth’s Moon); Charon is 750 miles across. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

In the end, this apparent large impact might only be a contrast effect or worse, an artifact of over-processing, but there’s no denying its strong resemblance to foreshortened, shadow-filled craters seen on the Moon and other moons. It’s also encouraging that an earlier photo from June 27 shows the same feature. But the “crater” is just so … big! Its size seems disproportionate to the Pluto’s globe and recalls Saturn’s 246-mile-wide moon Mimas with its 81-mile-wide crater Herschel.

Pluto (right) and Charon, with its unusual dark north polar cap or “anti-cap” in a photo taken by New Horizons’ long-range camera on June 19, 2015. Pluto’s 1,471 miles in diameter; Charon’s half that size. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Pluto (right) and Charon, showing an unusual dark north polar cap or “anti-cap” in a photo taken by New Horizons’ long-range camera on June 19, 2015. The two were about 20 million miles away at the time. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Astronomers speculate the impact that gouged out Herschel came perilously close to shattering the moon to pieces. If it does turn out to be an crater, Pluto’s surface opposite the impact will likely show many fractures. Not to be outdone, the dwarf planet’s largest moon, Charon, is starting to show a personality of its own with a prominent dark north polar cap.

Since polar caps are normally bright, icy features, some have referred to this one as an “anti-polar cap”. Speaking of ice, the bright rim around Pluto in the photo above may be nitrogen frost condensing out of Pluto’s scant atmosphere as it slowly recedes from the Sun. Think how cold it must have to get for nitrogen to freeze out. How about -346° F (-210° C)! For new images of the Pluto system, be sure to check the New Horizons LORRI gallery page.

Dawn took this photo of an intriguing pyramidal mountain on Ceres on June  14 from an altitude of 2,700 miles. It rises 3 miles above a relatively smooth surface. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Dawn took this photo of an intriguing pyramidal mountain (top center) on Ceres on June 14 from an altitude of 2,700 miles. It rises 3 miles above a relatively smooth surface. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Closer to home, new photos of Ceres show a peculiar, pyramid-shaped mountain towering 3 miles (5 km) high from a relatively smooth region between two large craters. Mountains poking from crater floors aren’t unusual. They’re tossed up after the crust later rebounds after a large impact. What makes this one unusual is the lack of an associated crater. Moreover, the mountain’s pale hue could indicate it’s younger than the surrounding landscape. As far as we can tell, it’s the only tall mountain on the face of the dwarf planet.

Another more overhead view of the mountain (right of center) taken by NASA's Dawn probe on June 6. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Another more overhead view of the mountain (right of center) taken by NASA’s Dawn probe on June 6. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Cropped version of the photo above. Notice the striations on the mountainside possibly from landslides. Credit:
Cropped version of the photo above. Notice the striations on the mountainside possibly from landslides. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The Dawn team also photographed that cluster of white spots again, this time with a very shot exposure in to eke out more details. What do you think? If you’re as interested in asteroids as I am, Italian astrophysicist Gianluca Masi, a frequent photo contributor to Universe Today, will host a special live Asteroid Day event today starting at 6 p.m. CDT (23:00 UT). Masi will review near-Earth asteroids, explain discovery techniques and observe several in real time.

The Dawn team greatly underexposed Ceres in order to tease out more details from the white spot cluster in this image made on June 15 from 2,700 miles altitude. I've lightened the limb of Ceres, so you can see the context better. Credit:
The Dawn team greatly underexposed Ceres in order to tease out more details from the white spot cluster in this image made on June 15 from 2,700 miles altitude. I’ve lightened the limb of Ceres to provide context. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Dawn photographed the large crater at left along with an interesting chain of craters and possible fault or collapse features. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Dawn photographed the large crater at left along with an interesting chain of craters and possible fault or collapse structures. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Pluto Reveals Many New Details In Latest Images

Hey Pluto, it’s great to see your face! Since sending its last batch of images in April, NASA’s New Horizons probe lopped off another 20 million miles in its journey to the mysterious world.  Among the latest revelations: the dwarf planet displays a much more varied surface and the bright polar cap discovered earlier this spring appears even bigger.

Comparison of the April image of one hemisphere of Pluto with nearly the same hemisphere photographed in May. have been rotated to align Pluto's rotational axis with the vertical direction (up-down), as depicted schematically in the center panel. Between April and May, Pluto appears to get larger as the spacecraft gets closer, with Pluto's apparent size increasing by approximately 50 percent. Pluto rotates around its axis every 6.4 Earth days, and these images show the variations in Pluto's surface features during its rotation. Credit: NASA
Comparison of the April image of one hemisphere of Pluto with the same hemisphere photographed in May. The photos have been rotated to align Pluto’s rotational axis with the vertical direction (up-down), as shown schematically in the center panel. Between April and May, Pluto grew larger as the spacecraft got closer, with Pluto’s apparent size increasing by approximately 50%. Pluto rotates around its axis every 6.4 Earth days; this and the images below show the variations in Pluto’s surface features during its rotation. Credit: NASA

“These new images show us that Pluto’s differing faces are each distinct; likely hinting at what may be very complex surface geology or variations in surface composition from place to place,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado.

Compare Pluto's polar cap (white spot at top of the globe), first seen in April (left) with the latest image taken on May 10. Approximately the same face of Pluto is shown in both images. The cap's extent varies with longitude. Credit: NASA
Compare Pluto’s polar cap (white spot at top of the globe), first seen in April (left) with the latest image taken on May 10. Approximately the same face of Pluto is shown in both images. The cap’s extent varies with longitude. Credit: NASA

Mission scientists caution against over-interpreting some of the smaller details. The photos have been processed using a method called deconvolution, which strips away the out-of-focus information to enhance features on Pluto. Deconvolution can occasionally add “false” details or artifacts, so the smallest features in these pictures will need to be confirmed by images taken from closer range in the next few weeks.

Pluto compared on
Pluto compared on April 16, 2015 and May 12. Credit: NASA

Compared to recent photos of Ceres, the other dwarf planet in the limelight this season, Pluto shows only light and dark blotches. That’s how Ceres started out too. All those variations in tone and texture suggest a fascinating and complex surface. And it’s clear that the polar cap — whatever it might ultimately be — is extensive and multi-textured. The images were taken from a little less than 50 million miles (77 million km) away or about the same distance Mars is from Earth during a typical opposition.

New Horizons current position along with
New Horizons current position and particulars on May 28, 2015. Credit: NASA

Watch for dramatic improvements in the images as New Horizons speeds toward its target, covering 750,000 miles per day until closest approach on July 14. By late June, they’ll have four times the resolution; during the flyby that will improve to 5,000 times. The spacecraft is currently 2.95 billion miles from Earth. Light, traveling at 186,00o miles per second, requires 8 hours and 47 minutes – the length of a typical work day – to make the long round trip.

Ceres Bright Spots Sharpen But Questions Remain

The latest views of Ceres’ enigmatic white spots are sharper and clearer, but it’s obvious that Dawn will have to descend much lower before we’ll see crucial details hidden in this overexposed splatter of white dots. Still, there are hints of interesting things going on here.

Comparison of the most recent photos of the white spots taken Dawn's current 4,500 miles vs. 8,400 miles on May 3. Credit:
Comparison of the most recent photos of the white spots taken Dawn’s current 4,500 miles vs. 8,400 miles on May 4. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The latest photo is part of a sequence of images shot for navigation purposes on May 16, when the spacecraft orbited 4,500 miles (7,200 km) over the dwarf planet. Of special interest are a series of troughs or cracks in Ceres crust that appear on either side of the crater housing the spots.

While the exact nature of the spots continues to baffle scientists, Christopher Russell, principal investigator for the Dawn mission, has narrowed the possibilities: “Dawn scientists can now conclude that the intense brightness of these spots is due to the reflection of sunlight by highly reflective material on the surface, possibly ice.”

Two views of an impact exposing water ice on Mars. The bright material conspicuous in this image was excavated from below the surface and deposited nearby by a 2008 impact that dug a crater about 8 meters (26 feet) in diameter. The extent of the bright patch was large enough for the Compact Reconnaissance Imaging Spectrometer for Mars, an instrument on NASA's Mars Reconnaissance Orbiter, to obtain information confirming the material to be water ice. Credit: NASA/JPL-Caltech/University of Arizona
The bright material in both photos was excavated from below the surface and deposited nearby by a 2008 impact that dug a crater about 26 feet (8 meters) in diameter. The extent of the bright patch was large enough for the Compact Reconnaissance Imaging Spectrometer for Mars, an instrument on NASA’s Mars Reconnaissance Orbiter, to obtain information confirming it as water ice. Credit: NASA/JPL-Caltech/University of Arizona

We’ve seen ice exposed by meteorite / asteroid impact before on Mars where recent impacts have exposed fresh ice below the surface long hidden by dust. In most cases the ice gradually sublimates away or covered by dust over time. But if Ceres’ white spots are ice, then we can reasonably assume they must be relatively new features otherwise they would have vaporized or sublimated into space like the Martian variety.

NASA's Hubble Space Telescope took these images of the asteroid 1 Ceres over a 2-hour and 20-minute span, the time it takes the Texas-sized object to complete one quarter of a rotation.
NASA’s Hubble Space Telescope took these images of the asteroid 1 Ceres over a 2-hour and 20-minute span, the time it takes the Texas-sized object to complete one quarter of a rotation. The observations were made in visible and in ultraviolet light. Hubble took the snapshots between December 2003 and January 2004. Credit: NASA, ESA, J. Parker, P. Thomas and L. McFadden

Much has been written – including here – that these spots are the same as those photographed in much lower resolution by the Hubble Space Telescope in 2004. But according the Phil Plait, who writes the Bad Astronomy blog, that’s false. He spoke to Joe Parker, who was part of the team that made the 2004 photos, and Parker says the Dawn spots and Hubble spots are not the same.

Could the spots have formed post-2004 or were they simply too small for Hubble to resolve them? That seems unlikely. The chances are slim we’d just happen to be there shortly after such a rare event occurred? And what happened to Hubble’s spot – did it sublimate away?


Video compiled from Dawn’s still frames of Ceres by Tom Ruen. Watch as the spots continue to reflect light even at local sunset.

Watching the still images of Ceres during rotation, it’s clear that sunlight still reflects from the spots when the crater fills with shadow at sunset and sunrise. This implies they’re elevated, and as far as I can tell from the sunrise photo (see below), the brightest spots appear to shine from along the the side of  a hill or mountain. Could we be seeing relatively fresh ice or salts after recent landslides related to impact or tectonic forces exposed them to view?

 The crater with white spots shortly after sunrise. The bright spots appear to be on a central mountain. It's unclear if the pair of spots below the bright pair are situated on a rise or the flat floor. Credit: NASA
Single from from the video shows the white spots shortly after sunrise. The brightest appear to be located on a central mountain peak.  It’s unclear if the pair of spots below the bright pair are situated on a rise or the flat floor. Credit: NASA

Let’s visit another place in the Solar System with an enigmatic white spot, or should I say, white arc. It’s Wunda Crater on Uranus’ crater-blasted moon Umbriel. The 131-mile-wide crater, situated on the moon’s equator, is named for Wunda, a dark spirit in Aboriginal mythology. But on its floor is a bright feature about 6 miles (10 km) wide. We still don’t know what that one is either!

The moon Umbriel,  727 miles in diameter, with Wunda Crater and its bright internal ring of unknown origin. The moon's equator is vertical in this photo. Credit: NASA
The moon Umbriel, 727 miles in diameter, with Wunda Crater and its bright internal ring of unknown origin. The moon’s equator is vertical in this photo. Credit: NASA

Ceres’ White Spots Multiply in Latest Dawn Photos

We don’t know exactly what those mysterious white spots on Ceres are yet, but we’re getting closer to an explanation. Literally. The latest images from the Dawn spacecraft taken a mere 8,400 miles from the dwarf planet Ceres reveal that the pair of  spots are comprised of even more spots. 

“Dawn scientists can now conclude that the intense brightness of these spots is due to the reflection of sunlight by highly reflective material on the surface, possibly ice,” said Christopher Russell, principal investigator for the Dawn mission from the University of California, Los Angeles.

This animation shows a sequence of images taken by NASA's Dawn spacecraft on May 4, 2015, from a distance of 8,400 miles (13,600 kilometers), in its RC3 mapping orbit. The image resolution is 0.8 mile (1.3 kilometers) per pixel. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
This animation shows a sequence of images taken by NASA’s Dawn spacecraft on May 4, 2015, from a distance of 8,400 miles (13,600 km), in its RC3 or science mapping orbit. The image resolution is 0.8 mile (1.3 km) per pixel. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Dawn recently concluded its first science orbit, making a 15-day full circle around Ceres while gathering data with its suite of science instruments. This past Saturday, May 9, its ion engine fired once again to lower the spacecraft to its second science orbit which it will enter on June 6. On that date, the probe will hover just 2,700 miles (4,400 km) above the dwarf planet and begin a comprehensive mapping of the surface. Scientists also hope the bird’s eye view will reveal clues of ongoing geological activity.


Check out this great video compiled from Dawn’s still frames of Ceres by Tom Ruen. Almost feels like you’re there.

There’s no doubt a lot’s been happening on Ceres. One look at all those cracks hint at either impact-related stresses some kind of crustal expansion. Geological processes may still make this little world rock and roll.

In this uncropped single frame, not only are multiple white spots visible but also long, parallel cracks or troughs in Ceres' surface. Credit:
In this uncropped single frame, not only are multiple white spots visible but also long, roughly parallel cracks or troughs in Ceres’ surface. Are they impact-related or caused by some other stress? Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Fortunately, we won’t have to wait till next month for more photos. NASA plans to pause the probe twice on the way down to shoot and send fresh images.

The Solar System’s ‘Yearbook’ is About to Get Filled In

Lined up like familiar faces in your high school yearbook, here are images of the 33 largest objects in the Solar System, ordered in size by mean radius. Engineer Radu Stoicescu put this great graphic together, using the highest resolution images available for each body. Nine of these objects have not yet been visited by a spacecraft. Later this year, we’ll visit three of them and be able to add better images of Ceres, Pluto and Charon. It might be a while until the remaining six get closeups.

“This summer, for the first time since 1989,” Stoicescu noted on reddit, “we will add 3 high resolution pictures to this collection, then, for the rest of our lives, we are not going to see anything larger than 400 km in high definition for the first time. It is sad and exciting at the same time.”

Dawn will enter orbit at Ceres approximately March 6, 2015, four months before New Horizons flies past Pluto and Charon.

But a comprehensive Solar System yearbook might never be completed. Not only will there likely be new dwarf planets discovered in the Kuiper Belt, uUnless things change in the budgetary and planetary missions departments for any of the world’s space agencies, the remaining six unvisited objects in the graphic above will likely remain as “fuzzy dots” for the rest of our lives.

If you like the graphic above, you can see more imagery and space discussions at Stoicescu’s reddit page.

For more Solar System yearbook-like imagery, Emily Lakdawalla has also created some wonderful graphics/montages of our Solar System, like this one:

Every round object in the solar system under 10,000 kilometers in diameter, to scale. Montage by Emily Lakdawalla. Data from NASA / JPL and SSI, processed by Gordan Ugarkovic, Ted Stryk, Bjorn Jonsson, and Emily Lakdawalla.
Every round object in the solar system under 10,000 kilometers in diameter, to scale. Montage by Emily Lakdawalla. Data from NASA / JPL and SSI, processed by Gordan Ugarkovic, Ted Stryk, Bjorn Jonsson, and Emily Lakdawalla.

As Emily wrote in the accompanying blog post, “Just look at all of these worlds, and think about how much of the solar system we have yet to explore. Think about how much we have to learn by orbiting, and maybe even landing on, those planet-sized moons. Think about how Pluto isn’t the end of the planets, it’s the start of a whole new part of the solar system that we’ve never seen before, and how seeing Charon is going to clue us in to what’s happening on a dozen other similar-sized, unvisitably far worlds.”