December 9, 2013
Mars is back in the headlines, and this time the chances of finding fossil life on the Red Planet have increased.
Last month a team led by Munir Humayun of Florida State University reported on the oldest Martian rock discovered so far. The meteorite, found last year in North Africa, dates from about 4.4 billion years ago, a mere 100 million years or so after Mars became a planet. Named “Black Beauty” because of its dark glossy appearance, the rock known formally as NWA7533 originated when water flowed on the surface of Mars—a time when we would expect that life arose on Mars, if it ever did. Black Beauty’s elemental and mineralogical composition gives us a glimpse of environmental conditions during that intriguing period of Martian history.
It appears that the meteorite came from the southern highlands of Mars, a region about which we know relatively little. The landscape there is covered with craters, the largest of which is the Hellas Basin, about seven kilometers deep and more than 2,000 km across. The basin resulted from an impact that must have had planet-changing repercussions at a time when Mars was warmer and wetter than today. We see evidence of that wetter past in the networks of river systems and valleys found throughout the southern highlands.
New reports from NASA’s Curiosity rover science team suggest that even long after that planet-changing event, Mars retained habitable environments—regions where life could have thrived, at least on a temporary basis, for a minimum of tens of thousands of years, and perhaps up to tens of millions of years. This is the most astonishing result from the analysis of fine-grained sedimentary rocks at Gale Crater, where Curiosity landed 16 months ago. John Grotzinger and his team analyzed these rocks and came to the conclusion that the so-called Sheepbed Mudstones formed in an ancient lake that would have been suitable to support life on Mars.
None of the new data, either from Black Beauty or the Curiosity rover, can prove that life actually existed on Mars. Black Beauty was discovered in the Sahara desert, and has likely been thoroughly contaminated by Earth life since it fell from the sky. Even if it contained some remnant of Martian life, it would be nearly impossible to distinguish it conclusively from Earth life, especially since we don’t have much of an idea what the chemical characteristics of Martian life would be.
The most intensively studied Martian meteorite, known as ALH 84001, was found in Antarctica, and scientists were able to rule out Earthly contamination within the interior of the rock. But the claim in 1996 that this meteorite contained fossilized life is still very controversial. While hardly anyone believes anymore that the images interpreted as possible microfossils actually represent Martian organisms, magnetic chains discovered in the rock and the close association of reduced and oxidized regions within the meteorite can best be explained by biological processes.
The new Martian meteorite will improve our knowledge about geological and environmental conditions in the southern highlands of Mars around 4.4 billion year ago, as well as the period about two billion years ago when volcanic activity added newer material to the rock that later became the meteorite. Amazingly, even that younger part of the meteorite was rich in water, having about 10 times more than comparable meteorites. In light of the new Curiosity results, that no longer seems surprising.
The best way to answer some of these questions, of course, would be to bring back samples directly from Mars with a Mars Sample Return Mission or a human expedition. But until that happens, Martian meteorites and the rocks studied by Curiosity are the next best thing.
Dirk Schulze-Makuch is a professor of astrobiology at Washington State University and has published seven books related to the field of astrobiology. He is also adjunct professor at the Beyond Center at Arizona State University.
December 6, 2013
So far, Asia’s new solar system missions seem to be proceeding without a hitch.
China’s Chang’e-3 spacecraft entered lunar orbit late Friday afternoon Beijing time, and will attempt the country’s first robotic moon landing on December 14. Once on the surface, the main lander will deploy a desk-size wheeled rover named Yutu (Jade Rabbit) to roam the lunar landscape.
Meanwhile, India’s Mars Orbiter Mission, nicknamed Mangalyaan (“Mars craft”), escaped the gravitational pull of Earth on December 4, and is now in interplanetary space, headed for Mars. The next milestone is scheduled for December 11 — the first of three rocket burns to tweak the spacecraft’s trajectory before its arrival at the Red Planet in September.
Chang’e-3 is scheduled to land on the flat floor of a large crater, a region known as Sinus Iridum. The lander is equipped with solar power arrays and reportedly also has a nuclear power source. Yutu carries instruments not unlike those on NASA’s Mars rovers, including a rock abrasion tool, like a small drill, for boring into rocks so their fresh surfaces can be photographed with very high-resolution cameras.
Here’s a good animation showing the Chang’e-3 mission from launch to lunar exploration:
December 2, 2013
Between them, Steve Hinton and his son Steven have won six championships in the Unlimited class at the Reno air race.
Join them at the National Air and Space Museum on December 3 as they discuss their winning ways as part of the GE Aviation Lecture series.
Admission to the Lockheed Martin IMAX Theater is free, or you can watch the 8:00 p.m. lecture on the web.
November 26, 2013
Remember those exciting new Earth-viewing satellites we told you about in our September issue? They’re starting to launch into space, as promised.
Last Thursday a Russian Dnepr rocket delivered 32 satellites to orbit, among them SkySat-1, the first of Skybox Imaging’s constellation of Earth cameras. On the same Dnepr were two of Planet Labs’ tiny cubesats, called Doves. The first operational “flock” of Doves is due to reach space in mid-December, on the same Antares rocket that carries the Cygnus 2 cargo vehicle to the International Space Station.
Yesterday, a Progress cargo vehicle blasted off from Baikonur, Kazakhstan, also bound for the space station. Onboard is an Earth-viewing camera built by Urthecast of Vancouver.
The age of near-real-time, low-cost Earth imagery from space is about to begin.
Here’s a video of the Dnepr launch:
November 21, 2013
There have been other presidential airplanes, but the one known, prosaically, by its serial number — SAM 26000 — is the most famous by far. It’s the one Jackie Kennedy had a hand in designing, the first built specifically to transport the U.S. head of state around the world, and the scene, 50 years ago, of some of the most emotional moments in presidential history.
On November 22, 1963, 28 people crowded into the staff room of this specially outfitted Boeing 707 to watch Lyndon Johnson take the oath of office, with the widow of assassinated President John F. Kennedy standing at his side. Just inside the rear door of the aircraft, in the aft galley, sat her husband’s coffin. The presidential party had arrived in Dallas only three hours earlier, on this same airplane.
The sites associated with that awful day have become part of American lore — Dealey Plaza, the book depository, the grassy knoll. For this 50th anniversary, two writers turned their attention to the airplane that carried one U.S. president to Dallas and brought a different one back to Washington on the same day. Washingtonian editor Garrett Graff has written a slim book, Angel is Airborne, set inside SAM 26000 on the day of the assassination (you can read it here). Esquire writer Chris Jones covers the same subject in his article “The Flight From Dallas.” Both rely heavily on previously published accounts, but they still make riveting reading, if only to remind us of all the accidents of timing that led some 40 people — including future LBJ aides Jack Valenti and Bill Moyers — to be on board the airplane during those climactic hours.
Among them was the man who took the pictures of LBJ’s hastily arranged swearing-in. As a White House photographer, Cecil Stoughton had shot many of the iconic images we associate with Kennedy’s Camelot. Before that, he had been a wartime photographer in Guadalcanal, and had documented the early space program from Cape Canaveral (he was on the recovery ship when the monkeys Able and Baker splashed down in 1959).
At the time of the assassination, Stoughton was riding in the motorcade several cars back from the president. He heard shots, but couldn’t see what had happened. In fact, it wasn’t until he arrived at Parkland Hospital that he learned Kennedy had been hit and was likely dead. Then, as Stoughton recalled it years later in an oral history interview, as he was standing around at the hospital:
Out of the corner of my eye I saw Mr. Johnson, Mrs. Johnson, [Secret Service agent] Rufus Youngblood and a couple of other people making mad dashes for the door, which was behind me….I kind of nodded. “Where’s he going?” And [another aide] said “The president’s going to Washington.” That was my clue that the president I came with was no longer there, and I said “Well, so am I.”
Stoughton climbed into a car and raced to Love Field, where the presidential airplane was waiting on the tarmac.
A policeman drove us out. There were four of us in the car. We made a mad dash to the airport using a different route because you didn’t know which way they had gone, really, and they were under security cover anyway, no radios. So we came up to Love Field and we came in the wrong entrance. It turned out that we came in towards the active runway and, actually, we crossed the active runway and came barreling down this active runway, under the guns, we found out later, of security guys who had been posted there just in the last five minutes. We almost got shot, because, “What’s this black car?” It might be official and all that, but here it comes charging towards Air Force One.
The photographer rushed up to pilot Jim Swindal, whom he knew, and got the okay to come aboard. Within an hour, with the plane still on the ground, Stoughton took some of the most recognized photos of the 20th century while standing on a couch looking down. In all the pictures, according to Graff, he was careful to frame Mrs. Kennedy from the waist up so the blood stains on her skirt wouldn’t show.
Stoughton didn’t fly back to Washington with the new president — he rushed off to have his negatives developed instead.
By the time they were dried and we’d made all [the] selections and so forth, the plane had landed at Andrews [AFB] one hour and fifty-two or -three minutes later; fastest time in history, I guess, from Dallas to Andrews because they got into a tremendous tail wind. By the time they got there and they were taxiing on the ground, someone told me [who] was on the plane that they put the pictures on the [TV] screen. AP had moved them. They put them on the screen and the new President then saw himself being sworn in just two hours ago.
Today SAM26000 is retired and on display at the National Museum of the Air Force in Dayton, Ohio. For the 50th anniversary of the fateful flight to Dallas, the museum asked photographer Lyle Jansma, who also created our gallery of inside-the-cockpit views, to make a virtual tour of the inside of the historic airplane.
Look around the (since remodeled) room where LBJ was sworn in, from the photographer’s vantage point:
Or take the full tour of the airplane:
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