On June 21, , TRACE took its last image, after millions of images before the last and 12 successful years in orbit. Publish Date:.
- Women Filmmakers in Mexico: The Country of Which We Dream?
- LSAT PrepTest 13!
- Stay Connected.
- The Oracle of Rama: Indias Renowned Oracle.
- Refinement Calculus: A Systematic Introduction (Texts in Computer Science).
May 22, Full Name:. It is dry and cold, plunging down as far as degrees Fahrenheit. Its thin atmosphere cannot block ultraviolet radiation from space, which would devastate any known living thing on the surface of the planet. But Mars, which is as old as Earth, might have been more hospitable in the past. The gullies and dry lake beds that mark the planet indicate that water once flowed there.
In other words, early Mars was a lot like early Earth. If Mars had been warm and wet for millions or even billions of years, life might have had enough time to emerge. When conditions on the surface of Mars turned nasty, life may have become extinct there. But fossils may have been left behind.
He had just earned a PhD at the University of Portsmouth, where he was studying bacterial biofilms that can absorb radioactivity from contaminated steel in nuclear facilities. Biofilms had formed and spread through cracks into its interior. The controversy has raised a profound question in the minds of many scientists: What does it take to prove the presence of life billions of years ago? In particular, Schopf had proposed that his fossils were photosynthetic bacteria that captured sunlight in a shallow lagoon. But Brasier and Steele and co-workers concluded that the rocks had formed in hot water loaded with metals, perhaps around a superheated vent at the bottom of the ocean—hardly the sort of place where a sun-loving microbe could thrive.
NASA Discovered Evidence of Life on Mars 40 Years Ago, Then Set It On Fire | Live Science
And microscopic analysis of the rock, Steele says, was ambiguous, as he demonstrated one day in his lab by popping a slide from the Warrawoona chert under a microscope rigged to his computer. Are we looking at life? Maybe, maybe. You can see how easily you can fool yourself. Analyzing his samples further, he found that they were made of a form of carbon known as kerogen, which would be expected in the remains of bacteria.
The disagreement is typical of the fast-moving field. Other recent claims also are under assault. Ayear ago, a team of scientists made headlines with their report of tiny tunnels in 3. The scientists argued that the tunnels were made by ancient bacteria around the time the rock formed. But Steele points out that bacteria might have dug those tunnels billions of years later. Such debates may seem indecorous, but most scientists are happy to see them unfold.
To be sure, the debates are about subtleties in the fossil record, not about the existence of microbes long, long ago. Even a skeptic like Steele remains fairly confident that microbial biofilms lived 3. It will also guide their search for signs of life elsewhere in the universe—starting with Mars. The chemistry of rock it sampled from a plain called Meridiani Planum indicated that it had formed billions of years ago in a shallow, long-vanished sea. The past year has brought a flurry of tantalizing reports. An orbiting probe and ground-based telescopes detected methane in the atmosphere of Mars.
In February, reports raced through the media about a NASA study allegedly concluding that the Martian methane might have been produced by underground microbes. NASA headquarters quickly swooped in—perhaps worried about a repeat of the media frenzy surrounding the Martian meteorite—and declared that it had no direct data supporting claims for life on Mars.
From Earthrise to the black hole: astronomy's most famous images
But just a few days later, European scientists announced that they had detected formaldehyde in the Martian atmosphere, another compound that, on Earth, is produced by living things. The texture of the landscape, they argued, shows that the area was a frozen ocean just a few million years ago—not long, in geological time. Afrozen sea may still be there today, buried under a layer of volcanic dust. Andrew Steele is one of the scientists designing the next generation of equipment to probe for life on Mars.
One tool he plans to export to Mars is called a microarray, a glass slide onto which different antibodies are attached. Each antibody recognizes and latches onto a specific molecule, and each dot of a particular antibody has been rigged to glow when it finds its molecular partner. Steele has preliminary evidence that the microarray can recognize fossil hopanes, molecules found in the cell walls of bacteria, in the remains of a 25 million- year-old biofilm.
As armed Norwegian guards kept a lookout for polar bears, the scientists spent hours sitting on chilly rocks, analyzing fragments of stone. The answer may be maybe not. The Event Horizon Telescope relies on a technique called interferometry.
Similarly, with the EHT, the signals from all eight telescopes have to be combined and fed through a computer to turn a mountain of incomprehensible blips into a visual picture. This presented an unprecedented computational challenge: the amount of data collected was so enormous that it had to be physically shipped to a central location, the MIT Haystack observatory, in the form of half a tonne of hard drives. Developing new, sophisticated algorithms was a crucial part of turning the EHT data into an image. These needed to not only combine the data but also filter out noise caused by factors like atmospheric humidity, which warps radio waves, and precisely synchronising the signals captured by the far-flung telescopes.
While still studying at MIT, the computer scientist Katie Bouman came up with a new algorithm to stitch together data collected across the EHT network. At one stage, this involved the collaboration splitting into four separate teams which analysed the data independently until they were absolutely confident of their findings.
Download Trace Nasa Facts
Quick guide What are black holes? Play Video.
Facebook Twitter Pinterest. Topics Black holes. Space Astronomy news. Reuse this content.