More than four decades ago, the Soviet Union dropped a heavily instrumented craft onto the Martian surface intact — only to have it fall silent seconds later. After a prolonged search, a group of Russian space enthusiasts think they've finally spotted it in NASA imagery.

By 1971, the United States had won the Moon Race handily, but interplanetary bragging rights were still very much up for grabs. That summer both the U.S. and U.S.S.R. launched pairs of spacecraft toward the Red Planet. NASA lost Mariner 8 during launch, but Mariner 9 slipped into orbit around Mars as planned and mapped most of its surface (once a globe-engulfing dust storm abated).

mars 3 lander

A model of the Mars 3 landing capsule, which successfully landed on the Red Planet in 1971 (five years before the Vikings) but mysteriously fell silent about two minutes later.

NSSDC

The Soviet craft, Mars 2 and 3, were more complex, each consisting of an orbiter and a heavily instrumented lander. Although the Mars 2 lander crashed during descent, its counterpart fared better. On December 2, 1971, Mars 3's lander thumped roughly onto the surface, opened its four petal-shaped covers, and began transmitting a panoramic TV image to its orbiter. But the signal stopped abruptly after just 14½ seconds — only part of a single, blank image reached Earth. To this day it's unclear whether the lander or the radio relay on the orbiter failed.

Now one aspect of this decades-old mystery might finally be resolved. The Mars 3 lander dropped into the broad crater Ptolemaeus at 45° S, 158° W, though its exact location has remained uncertain. However, the super-sharp HiRISE camera on NASA's Mars Reconnaissance Orbiter has imaged a set of objects on the surface that appear to be the lander, along with its heat shield, retrorocket, and parachute.

The identifications weren't made by NASA scientists but instead by a group of Russian space enthusiasts led by Vitaliy Egorov. Last November they painstakingly combed through a HiRISE image of the landing area taken in 2007, trying to match features with Egorov's computer-generated models of how the various pieces might appear from orbit. It wasn't an easy task: that single image contained 1.8 billion pixels, enough to fill about 2,500 computer screens.

Mars 3's lander?

This composite color image from the HiRISE camera on NASA's Mars Reconnaissance Orbiter, taken March 10, 2013, appears to show the ill-fated Mars 3 lander and its retrorocket lying on the surface of Mars.

NASA / JPL / Univ. of Arizona

"When I suggested that our group begin searches, 15 or 20 people responded," Egorov says. "We examined all of the picture but didn't find the lander — enthusiasm quickly died away." So he continued to pore over the image on his own, finally spotting the Mars 3 candidate last New Year's Eve. Egorov has a web page that details the group's search effort (auto-translated to English here). "I think of it as a gift from Santa Claus or the Russian Father Frost," he muses.

Egorov then contacted Alexander Basilevskiy, a planetary scientist at Moscow's Vernadskiy Institute who's been aiding the search effort, and Basilevskiy in turn got word to Alfred McEwen (University of Arizona), who leads the HiRISE team. A second image of the area was beamed back to Earth on March 10th.

All the right pieces seem to be there, though they're strewn over about 3 miles (4½ km) of terrain. "My biggest doubts are about the heat shield," Egorov admits. But he's confident about the other identifications, noting that there are "too many arguments in favor of a real find." The HiRISE images, whose individual pixels correspond to 10 inches (25 cm) on the Martian surface, even reveal a beefy, 15-foot-long chain that connected the retrorocket to the landing capsule.

Mars 3's parachute?

Two HiRISE images, taken in red light on November 18, 2007 (left) and March 10, 2013, reveal a bright object on Mars that's about 25 feet (7½ m) across — the right size to be the main parachute for the Mars 3 lander. it looks whiter in the 2013 view, perhaps because wind has partially removed a dusty coating.

NASA / JPL / Univ. of Arizona

"The candidate parachute is the most distinctive and unusual feature in the images," McEwen comments on the HiRISE website. "It is an especially bright spot for this region, about 7.5 meters in diameter. The parachute would have a diameter of about 11 meters if fully spread out over the surface, so this is consistent."

McEwen plans to take more close-ups of the presumed spacecraft parts, but those views are unlikely to reveal why the spacecraft's transmission failed so abruptly.

Still, nothing in the HiRISE images suggests that any kind of malfunction occurred, bolstering the long-held view of many space experts that Mars 3 — rather than Viking 1, which arrived five years later — should be credited with the first successful landing on Mars.

Comments


Image of Robert Casey

Robert Casey

April 12, 2013 at 12:28 pm

Maybe one of the pedals failed to open up, thus the probe didn't get itself upright. And thus it ended up on its side. Thus the reason for the "horizon" in the image being at such a steep angle? I don't know where its camera is located on the probe, so I don't know if this is a reasonable possibility. Being on its side may cause the radio signal strength to be low and thus noisy, if the signal was mostly intended to aim upwards but ended up misaimed to some random spot on the horizon. Away from the orbiter. And maybe the wind caused it to roll over, thus killing the transmission? Lots of if's here...

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Bruce

April 14, 2013 at 8:08 am

After all that searching I do hope that Egorov has found what he was seeking, although, just to be clear, I don’t believe it was “a gift from Santa Claus or the Russian Father Frost”. The parachute images are the more convincing line of evidence. The other image that is thought to be of the retrorocket and lander has a sort of natural, fractal feel to it. That in itself isn’t enough to argue against this being a real find, but are the other unlabeled, smaller dark spots also pieces of this landing? If they were just natural parts of the Martian terrain then on statistical grounds the larger dark objects which are somewhat aligned with these smaller objects should be natural too. Clearly better imaging is needed here, which I hope will confirm Egorov’s discovery.

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RobJ

April 20, 2013 at 6:34 pm

It seems to me that the parachute candidate must be jutting up rather significantly, in order to shed as much dust as it apparently is able to. Therefore, either it is a large very light colored rock formation, or it is the parachute, but draped over something sufficiently tall and complex that can keep it from blowing away. If it was just the parachute, storm winds would have carried it away, or buried it.

It could be draped over a large rock formation. But when I examine an enlarged view of both parachute images, it is easy for me to imagine I see a 4 petaled object a little up and left of center, under the parachute (if it is the parachute). What are the odds that the parachute happened to drift down right on top of the lander? Terribly bad luck if so. There are no obvious dunes present, or other obvious evidence of prevailing winds. Could a near windless day contribute to lowering the odds?

A parachute that did not completely separate could cause a covered lander, and a blank picture, but would probably make an intact landing unlikely.

Just far out speculating, I should know better... next I'll be seeing faces on Mars!

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