A peek through the scraped and dinged up wheels of the Curiosity Rover taken with the close-up Mars Hand Lens Imager (MAHLI) camera Nov. 30, 2013. Credit: NASA/JPL-Caltech
I enjoy kicking back and looking over photos taken from other planets. There’s no better way to leave the Earth behind – if only for an hour – than digging through the archives. One of my favorite hangouts is the Mars Curiosity Rover raw image page. If you’ve followed this blog for a while, you already know how much I like sharing my favorite finds.
A field of little rocks embedded in soil photographed on Nov. 30. It’s currently mid-autumn in Mars’ southern hemisphere. Credit: NASA/JPL-Caltech
Curiosity landed at 4.5 degrees south latitude inside Gale Crater, placing it firmly in planet’s equatorial zone. Since the tilt of Mars’ axis is 25.2 degrees, nearly the same as Earth’s, the noonday sun is always high in the sky at Curiosity’s location just as it is for folks living near Earth’s equator. Would that the temperature would follow suit. Average daily temperatures in Gale Crater have ranged from -20 F (-29 C) during the day to -120 F (-85 C) at night in recent weeks.
View of nearby ridge with either the rim of Gale Crater or the foothills of the crater’s central peak Mt. Sharp on Nov. 29. Credit: NASA/JPL-Caltech
Mars’ atmosphere is too thin and its surface too dry to hold onto heat very long. Once the sun is up, the air temperature warms rapidly but then plummets after sunset. Still, -120 F isn’t all that bad. It’s still a tad warmer, at least for the moment, than -128.6 F (-89.2 C), the lowest temperature ever recorded on Earth at the (then) Soviet station at Vostok, Antarctica on July 20, 1983.
The wheels of the rover nudged a rock from its ancient resting place on Nov. 30, 2013. Credit: NASA/JPL-Caltech
It’s great to see Curiosity back up and running after engineers suspended science activities in mid-November when what appeared to be an internal shortin its power source was discovered. Luckily the minor electrical problem didn’t affect the rover’s capabilities. Curiosity continues its trek to Mt. Sharp, the layered mountain at Gale Crater’s center, while at the same time examining powdered rock sample gathered six months ago.
Click on any image to see a much-enlarged version perfect for at-home exploring.
Image showing the foothills of Mt. Sharp in Gale Crater on Nov. 29, 2013. Credit: NASA/JPL-Caltech
Eroded rock layers photographed on Nov. 1, 2013. Credit: NASA/JPL-Caltech
Fang-like rock feature photographed on Nov. 2, 2013. Credit: Credit: NASA/JPL-Caltech
After 14 months on Mars, Curiosity 1909 Lincoln cent is covered in a fine patina Martian dust and bits of soil. Photo taken on Oct. 2, 2013. Click to enlarge. Credit: NASA/ JPL-Caltech
When the Curiosity rover landed on Mars more than a year ago it brought with it an earthly artifact more than a century old – a 1909 Lincoln penny. For good luck? Maybe, but JPL engineers affixed the penny to the roving robot as a calibration target for its mobile, closeup camera named MAHLI (Mars Hand Lens Imager). While Abe’s looking a little dusty, his weathered face tells the story of 14 months on another planet.
The calibration target used by MAHLI to correct color casts in photos. The penny serves as a size reference. Credit: NASA/ JPL-Caltech
For MAHLI’s closeup pictures to accurately portray colors and brightness of the Martian landscape it needs a reference. The colored patches allow MAHLI to “white balance” or neutralize color casts common in digital images. The penny is a nod to the common practice by geologists of placing an object of known size in the frame to give the viewer a sense of scale.
Without something familiar in a picture as a reference, it’s hard to know the dimensions of things like soil grains and Mars pebbles.
Ken Edgett, principal investigator for MAHLI, bought the penny with his own money (coins in similar condition go for around $20 on eBay). Sure, mission planners could have used a standard ruler scale but opted instead for Edgett’s more poetic penny. NASA’s willingness to bend standard procedure to better connect with the public is a good thing.
The Mars penny all shiny before launch (left) and on Oct. 2. The coin is a 1909 VDB cent. The initials “VDB” of the coin’s designer, Victor David Brenner, are etched onto the reverse side. Credit: NASA/JPL-Caltech
But why a 1909 penny in particular? The Lincoln cent was first minted in 1909 to commemorate the centennial of President Lincoln’s birth. Curiosity was originally scheduled to launch in 2009, which happened to be the penny’s 100th anniversary. The connections across 200 years of time have an irresistible appeal to our romantic side.
Location of the calibration target and penny on the Curiosity rover. Credit: NASA
Delays pushed Curiosity’s launch date to 2011, but Lincoln kept his seat and now looks out across new territory every day.
The penny’s shine has disappeared beneath a fine coating of dust and bits of soil. I imagine NASA scientists wringing crucial data about the Martian atmosphere, winds and soil particle size as they study of the deposition of material on the coin’s face now and in the years ahead. Lincoln’s legacy reaches even to the Red Planet.
Beauty color photo of Comet ISON taken by astrophotographer Damian Peach on Sept. 24. ISON is a dusty comet. Much of that dust is blown back by light pressure from the sun to form the tail. Click to enlarge.
In just 4 days four Mars probes will focus cameras on Comet ISON as it makes its closest approach to the planet on Oct. 1. NASA’s Mars Reconnaissance Orbiter will study and photograph the comet from orbit on three days: Sept. 29, Oct. 1 and Oct. 2. Europe’s Mars Express orbiter, which began its ISON observing campaign on Sept. 21, will study the coma, the tenuous atmosphere that surrounds the comet’s icy nucleus. The probe will examine and photograph ISON through about October 5. As soon as photos are released, you’ll see them here.
The European Mars Express has already began its studies of Comet ISON from Mars orbit on September 21. The probe is the first European craft to visit another planet. Credit: ESA
Both the Curiosity and Opportunity rovers will also be pressed into service to spy ISON from the ground during the same time. Seen from Mars, the comet should glow about magnitude 2.5-3, plenty bright to see with the naked eye if you could somehow wish yourself there.
Comet ISON will shine at around magnitude 3 low in the northern sky in the constellation Lacerta the Lizard from the Curiosity rover’s location. Maps made with Stellarium
Amateur and professional astronomers have been watching Comet ISON evolve since its discovery on Sept. 21, 2012. It began as a dim 15th magnitude patch of haze and brightened very slowly. Amateurs reported a nice uptick in activity beginning late this summer into early fall. ISON now shines at about magnitude 11.5-12 (still faint and requiring a telescope to see) and sports a short tail pointing to the northwest. I was able to see the tail and brighter coma in my 15-inch (37 cm) scope without difficulty about a week ago in a dark sky just before dawn.
Comet ISON tomorrow morning shortly before the start of dawn. The comet’s moving east near the border of the constellations Cancer and Leo. It’s both physically close to Mars and very near the planet in the sky. Because of glare from the moon, a large amateur telescope is still required to see the comet.
Time exposure photos show a classic beauty of a comet with a bright, compact head and elegant tail. According to NASA’s Comet ISON Observing Campaign site,astronomers consider ISON “somewhat more active” that a typical comet. It’s kicking out a lot of dust right now as the sun’s heat vaporizes ice on the comet’s surface. That’s why we see a substantial tail in recent photos. Any guesses as to exactly how bright ISON will become when it zips nearest the sun on Thanksgiving Day are just that … educated guesses.
Movie made from images taken by NASA’s Deep Impact probe in mid-Jan. 2013
Astronomers use formulas based on comet size, distance and dust production rate to come up with brightness predictions. ISON could rival Venus for a short time on Nov. 28 or be substantially fainter or brighter. If it survives its searingly close passage of 745,000 miles (1.2 million km) from the sun’s surface, it will likely become a beautiful sight for northern hemisphere skywatchers during the first half of December. Southern hemisphere observers will have their best views before closest approach.
Much depends on the the comet’s size, currently estimated at 1.8 miles (3 km), pretty typical for a comet. The bigger the iceball, the better the chance of surviving the sun’s battering. Let’s hope ISON keeps it together.
Phobos, the larger of the two Martian moons at 17 miles across (27 km), creates an annular or ring eclipse as seen through the telephoto eye of the Mars Curiosity rover on Aug. 17. Credit: NASA/JPL-Caltech/Malin Space Science Systems/Texas A&M Univ.
Now that’s what I call crisp! NASA just released a series of high resolution pictures of Phobos transiting the sun on August 17. Taken with the 100mm telephoto lens mounted on Curiosity’s mast, they’re the sharpest ever of an eclipse from another world.
Curiosity paused during its drive toward Mt. Sharp and aimed its mast camera straight at the sun to make the sequence of views three seconds apart. Because the sun was nearly directly overhead at the time, Phobos was at its closest and biggest, covering the maximum amount of the sun’s disk as possible.
Sequence showing the sun before, during and immediately after an annular or “ring of fire” eclipse. This eclipse occurred on May 10, 1994 over central Illinois. Credit: Bob King
When one object passes in front of another but only blocks a small portion of it, astronomers call it a transit, but Phobos is big enough and its passage so central, this event is better described as an annular or ring eclipse. We have ring eclipses on Earth too, but because the moon is nearly spherical and much larger than Phobos, it leaves a much narrower “ring of fire”.
Two additional photos from the Phobos eclipse sequence showing the moon entering (left) and exiting the sun. Credit: NASA
Astronomers will measure the moon’s position as it moved across the sun to more precisely calculate Phobos’ orbit. As described in a recent blog, Phobos is gradually moving closer to Mars and will one day be broken to pieces. If you care to browse additional and original pix of the eclipse, check out this Curiosity raw image page and scroll down to the Mast Cam section.
Mars’ moon Deimos is occulted by Phobos on Aug. 1 as seen by Curiosity
What fun to live on a planet with TWO moons. Imagine stepping out into the Martian night to watch the moons Phobos and Deimos chase each other across the sky. NASA’s Curiosity rover did just that on Aug. 1 when mission control pointed its mast camera at the pair of tiny moons and snapped 41 photos as the larger and closer Phobos passed directly in front of little Deimos. In real time the “eclipse” took 55 seconds; the movie compresses that to 11. Even on Mars it was a marvelous night for a moondance.
With only one moon here on Earth, we miss out on the pleasures of dual moon gazing. The only thing that might come close is watching a cargo ship like the recent HTV-4 catch up and dock with the International Space Station.
Phobos orbits closer to Mars than Deimos and therefore completes a revolution around the planet more quickly, regularly overtaking its brother. The photos are the very first ever taken from Mars of an eclipse of one moon by the other.
Comparison showing how big the moons of Mars appear to be, as seen from its surface, in relation to the size that our moon appears to be seen from the Earth’s surface. Credit: NASA/JPL-Caltech/Malin Space Science Systems/Texas A&M Univ.
A 100mm telephoto lens was used to make the images which clearly show some of the larger craters on Phobos.
Both moons are tiny compared to our own. Deimos’ diameter is 7.5 miles (12 km) and Phobos 14 miles (22 km). It takes me longer to drive to work than cross the length of Deimos.
Even though Phobos is only about twice the size of Deimos, it appears much larger from the surface because it orbits much closer to the Red Planet – 3,700 miles (6,000 km) vs.12,400 miles (20,000 km).
Orbiting above the Martian equator and so close to the surface, Phobos can’t be seen from Mars’ polar regions. Its great speed also means it overtakes the planet’s rotation rate, rising in the west and setting in the east during the Martian night. Here on Earth, the moon moves in the same west to east direction but much more slowly, so that the faster-rotating Earth shuttles it from east to west during the night.
Phobos and Deimos up close as photographed by spacecraft. NASA scientists are studying the recent Curiosity images to determine precise orbits for the two moons as well as to gain a better understanding of the interior of Mars. Credit: NASA
Phobos’ tight orbit will ultimately lead to its demise. Its gravity induces tidal bulges in the crust of Mars which lag behind the fast-orbiting moon, causing it to gradually slow down and drop closer to the planet’s surface. In 50-100 million years Phobos will spiral in close enough for Mars’ gravity to break it to pieces. Deimos alone will remain to dimly light the Martian night.
View of Curiosity’s travels during its first year on Mars made August 2012 through July 2013. Credit: NASA
Next week on August 6 NASA’s Curiosity Rover will mark its first full year on the surface of Mars after one of the most dramatic touchdowns in the history of planetary exploration. In advance of the anniversary, NASA has released a movie made with the rover’s front hazard avoidance camera compressing 12 months of travels, scooping and drilling into 2 minutes.
View of the hilly rim of Gale Crater taken by Curiosity’s navigation camera on Aug. 1. Credit: NASA/JPL-Caltech
In case you’re wondering, there are 548 images in all and they were made with a fisheye camera lens. I particularly enjoy watching the shadows shift around the rover as the sun travels across the sky. We’ll take a closer look Curiosity’s finds during it first year on Mars early next week.
Mt. Sharp in Gale Crater looms five miles in the distance in this photo taken on July 8. Credit: NASA/JPL-Caltech
NASA’s Curiosity rover has set its sights for the fertile layers of Mt Sharp. You know the place – it’s that big hump on the horizon seen in many of the rover’s photos. The 3.4-mile-high (5.5 km) mountain has beckoned like a tempting Shangri-la for almost a year. Curiosity will roll across rocky terrain and a swath of potentially perilous sand dunes to reach the mountain’s base in a journey expected to take from 9 months to a year.
The photo at left is a closeup of chunk of ancient, pebble-riddled streambed on Mars with a particularly round pebble highlighted. It’s just under 1/2 inch (1 cm)across. At right, rocks are rounded into pebbles by the action of water in Amity Creek in Duluth, Minn. Credit: Bob King
After landing in August, rather than heading straight for the mountain, the car-sized rover detoured for more than six months to explore the Glenelg area, a region once braided by ancient streams. Curiosity found sedimentary rocks – desiccated riverbeds – chock full of rounded rocksshaped by waters cascading down the walls of Gale Craterseveral billion years ago. What a sight that must have been.
A rock in Yellowknife Bay is made of fine-grained sediments likely deposited under water. The rock was then fractured. Neutral pH waters deposited calcium sulfate, a form of gypsum, filling the crack. Credit: NASA/ JPL-Caltech
Rocks found in neighboring Yellowknife Bay area were found to contain clays that formed in the presence of water that was neither too alkaline nor acidic. Just right for life.
Likewise, detailed analysis by Curiosity’s Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments found elements essential for life to thrive and derive energy from its environment. Carbon, nitrogen, hydrogen, oxygen, sulfur and phosphorus all turned up. Those elements cover about 99% of what makes you you and me me.
The many layers of Mt. Sharp as seen from orbit. The 3.4-mile-high (5.5 km)mountain is really a huge deposit of materials similar to the layers in the walls of the Grand Canyon. Some are probably sedimentary, laid down by rivers or deposited in shallow seas; others possibly volcanic ash. Credit: NASA/JPL-Caltech
Indeed, the mission’s main science objective – finding evidence for a wet environment that had the conditions favorable for microbial life – has already been accomplished. But it’s not time to go home yet. After photographing, drilling and laser-zapping near its home turf, on July 4 Curiosity drove 59 feet (18 m) toward its new target; on July 7, a second drive added another 131 feet (40 m).
Mars Rover Curiosity looks back at wheel tracks (right foreground) made during the first drive into the “Glenelg” area 7 months ago. It’s now headed to Mount Sharp. Credit: NASA/JPL-Caltech
The many-layered base of Mt. Sharp are like pages of an ancient book to be turned over one at a time and studied for more clues about how Mars, once clearly a wet world friendly to life, turned dry, cold and hostile.
Phobos and Deimos, photographed here by the Mars Reconnaissance Orbiter, are tiny, irregularly-shaped moons that are probably strays from the main asteroid belt. Credit: NASA
Mars has two tiny moons. Phobos, the larger of them, is a spud-shaped object about 14 miles (22 km) across. Deimos(DEE-mohs or DYE-mohs) is a bumpy ball with an average diameter of 8 miles (13 km). Compared to our moon’s 2,159 mile (3,474 km) diameter, these guys are truly small potatoes.
Phobos passing overhead after sunset as seen by NASA’s Curiosity Rover last month. Time-lapse images were taken over 27 minutes.
Both the Curiosity rover and the Spirit and Opportunity rovers have taken time out from staring at the ground to occasionally look up at the moons of Mars at dusk or dawn. This week NASA released a short video of Phobos crossing through the sky after sunset. I like the fresh perspective. Seeing how the Martian sky differs from Earth’s makes that planet feel all the more an alien.
The Spirit Rover captured this transit of Phobos across the sun in 2005. Credit:NASA
If you could stand next to Curiosity and look up, you’d see that Phobos looks considerably smaller than Earth’s moon – only a third as big. Like our moon, it occasionally crosses in front of the sun, an event known as a transit.
While it’s too small to completely eclipse the sun it makes a striking silhouette in the video.
Deimos looks even smaller both because of its smaller size and it’s more than twice as far from the planet as Phobos. To the naked eye, Deimos would look like a brilliant star to everyone but keen-eyed skywatchers who might glimpse its teensy shape with a little concentration.
95 images of the Sun taken by Curiosity early in the mission were aligned to make this animation of Deimos transiting the Sun. Look closely and you’ll see it spinning. NASA / JPL / MSSS / Emily Lakdawalla
Because they resemble asteroids in size and composition, many astronomers think Deimos and Phobos were captured by Mars in the distant past. Nowadays they circle the planet in 30.3 hours (Deimos) and 7.6 hours (Phobos). While they’re every bit a moon like our own familiar orb, their behavior in the sky is something altogether different.
Phobos orbits at an average distance of 5,830 miles from Mars. Its extreme closeness to the planet means it moves rapidly across the sky as seen from the ground. Phobos rises in the west and sets in the east, crossing the sky in just 5 1/2 hours. Wait another 5 1/2 and you can watch it rise again in the west. On a long winter night, an astronaut on Mars would see Phobos rise twice and set once!
Deimos, which orbits further from the planet, rises in the east like a normal moon or star, but because its orbital period is so close to that of Mars (24 hours and 37 minutes) it moves very slowly upward from the horizon and doesn’t set in the west until almost 3 days later. One moon’s on steroids; the other putters about as if it had all the time in the world.
Colorized sunset shot by Curiosity’s black-and-white navcam from inside Gale Crater on June 22, 2013. Credit: NASA/JPL-Caltech
Curiosity also snapped a few photos of sunset on Mars on June 22. Martian sunsets and sunrises aren’t quite the visual feast they are on Earth. There’s so much dust suspended in the planet’s atmosphere, the sky glows a monotone reddish brown with a large pale blue aureole surrounding the sun.
True color photo of sunset over Gusev Crater on Mars taken by the Spirit Rover in 2005. Credit: NASA/JPL-Caltech
“The blue color comes from the way Mars’ dust scatters light,” says Mark Lemmon, associate professor of atmospheric sciences and a camera operator on the twin rovers Spirit and Opportunity.
“The blue light is scattered less, and so it stays near the sun in the sky, while red and green are all over the sky. On Earth, blue light is scattered all over by gas molecules, but there are not enough of these on Mars, which has less than 1 percent of Earth’s atmosphere, to accomplish this.”
Click on the photo and you’ll be taken to the billion-pixel interactive photo. Take a spin around or burrow in for closeup views of rocks, the rover and other details. Don’t forget to click the “full screen” view when you’re there. Credit: NASA
Wanna go to Mars? NASA just released a wonderful way to get there. With a few clicks of the mouse, you can zoom into a 360-degree scene comprised of nearly 900 pictures taken by Curiosity Rover from the Rocknest site. This is where the rover gathered and examined its first scoops of Martian soil.
Extreme zooming into the mosaic reveals multiple rock layers in Mt. Sharp. Credit: NASA
The picture is a mosaic of 850 telephoto frames and 21 wide angle views taken with the high-resolution, mast-mounted cameras. An additional 25 black-and-white pictures, mostly of the rover itself, were shot with the Navigation Camera. Put it on your screen and enjoy almost being there.
Curious white object found while zooming in to the right of a large rock below the right side of Mt. Sharp, the peak dominating the distant horizon. Credit: NASA
All the photos were taken between Oct. 5 and Nov. 16, 2012. You’ll notice different levels of atmospheric clarity depending on the day the images were shot. Have fun. If you find any little green men, do let us know.
Mars photographed with the C2 coronagraph on SOHO (Solar and Heliospheric Observatory) earlier this morning. SOHO uses a disk to block the sun’s light so astronomers can study its atmosphere called the corona. Mars appears next to the sun only because it’s in the same line of sight. The planet’s actually in the distant background. Credit: NASA/ESA
On April 17 the Red Planet and Earth will line up on opposite sides of the sun, an event called solar conjunction. Other than not being able to see Mars because it’s hidden in the solar glare, the event has one real consequence for earthlings. We’ll explore that in a minute. Let’s just say that since the two planets now sit at opposite ends of the seesaw, Mars is about as far away as it gets, winking at Earth across a distance of 225.7 million miles. Compare that to 35 million when we’re closest.
That’s OUT THERE. Even light, traveling at 186,000 miles per second, takes 20 minutes to cross the gulf separating Earth from Mars. That means a 40 minute round trip for radio communications between the Curiosity and Opportunity rovers and mission control.
Screen grab from the “How Far is it to Mars?” site that give you a taste for how far the moon and Mars are from Earth. Click to go there. Credit: David Paliwoda and Jesse Williams
How would you like to get a feel for that distance? Understanding that time is precious, we’ll go easy on you by making the journey when Mars is closest to Earth. Normally it would take about 150 days to travel to the Red Planet using current technology. We’ll arrive quicker by accelerating to 3 times the speed of light. Even at that pace, you might be surprised how long it takes to arrive. Click HERE or on the image above to take the free journey. Bon voyage!
Curiosity drilled two holes in the “John Klein” rock in early February and gathered the powdered tailings to analyze its composition. The holes are each 2/3″ or 16mm across. On March 26, the rover used its powerful ChemCam laser to repeatedly zap the drilled powder, creating a row of tiny pits. The vaporized rock emitted light that was analyzed by Curiosity to determine its makeup. Click to enlarge. Credit: NASA/JPL-Caltech
Let’s return to the consequences of a Mars solar conjunction. As described in this earlier blog, Mars’ close alignment with the sun does affect our ability to communicate with the Opportunity and Curiosity rovers. Signals sent from Earth pass directly along the sun’s line of sight en route to Mars where they could be corrupted by solar radiation storms and electrified particles in the sun’s corona.
Interesting white rocks scattered about where Curiosity is stationed in Yellowknife Bay in Gale Crater. Notice how rounded some of the other pebbles are – possibly from water erosion. Click to enlarge. Credit: NASA/JPL-Caltech
It’s no big deal if bits of information go missing in a transmission from Curiosity, but if a bad command were sent from Earth, it might cause the robot to seize up or do damage to itself. To avoid potential problems, NASA has suspended communications for the remainder of April. Each day, Curiosity sends daily beeps to Earth telling mission control “I’m still here.”
Cool “aerial” view of Mt. Sharp inside Gale Crater (where Curiosity landed) taken by the orbiting Mars Odyssey satellite. The layering in the mountain at upper left may have been made when sediments were deposited by flowing waters. Click to enlarge. Credit: NASA/JPL/ASU