Space Shuttle Columbia

NASA’s Chandra X-ray Observatory Celebrates 15th Anniversary.

Posted by

0


Fifteen years ago, NASA’s Chandra X-ray Observatory was launched into space aboard the Space Shuttle Columbia. Since its deployment on July 23, 1999, Chandra has helped revolutionize our understanding of the universe through its unrivaled X-ray vision.

Four new Chandra images of supernova remnants

Chandra, one of NASA’s current “Great Observatories,” along with the Hubble Space Telescope and Spitzer Space Telescope, is specially designed to detect X-ray emission from hot and energetic regions of the universe.

With its superb sensitivity and resolution, Chandra has observed objects ranging from the closest planets and comets to the most distant known quasars. It has imaged the remains of exploded stars, or supernova remnants, observed the region around the supermassive black hole at the center of the Milky Way, and discovered black holes across the universe. Chandra also has made a major advance in the study of dark matter by tracing the separation of dark matter from normal matter in collisions between galaxy clusters. It also is contributing to research on the nature of dark energy.

To celebrate Chandra’s 15th anniversary, four new images of supernova remnants – the Crab Nebula, Tycho, G292.0+1.8, and 3C58 – are being released. These supernova remnants are very hot and energetic and glow brightly in X-ray light, which allows Chandra to capture them in exquisite detail.

“Chandra changed the way we do astronomy. It showed that precision observation of the X-rays from cosmic sources is critical to understanding what is going on,” said Paul Hertz, NASA’s Astrophysics Division director in Washington. “We’re fortunate we’ve had 15 years – so far – to use Chandra to advance our understanding of stars, galaxies, black holes, dark energy, and the origin of the elements necessary for life.”

Chandra orbits far above Earth’s X-ray absorbing atmosphere at an altitude up to 139,000 km (86,500 mi), allowing for long observations unobscured by Earth’s shadow. When it was carried into space in 1999, it was the largest satellite ever launched by the shuttle.

“We are thrilled at how well Chandra continues to perform,” said Belinda Wilkes, director of the Chandra X-ray Center (CXC) in Cambridge, Massachusetts. “The science and operations teams work very hard to ensure that Chandra delivers its astounding results, just as it has for the past decade and a half. We are looking forward to more ground-breaking science over the next decade and beyond.”

Originally called the Advanced X-ray Astrophysics Facility (AXAF), the telescope was first proposed to NASA in 1976. Prior to its launch aboard the shuttle, the observatory was renamed in honor of the late Indian-American Nobel laureate, Subrahmanyan Chandrasekhar. Known to the world as Chandra (which means “moon” or “luminous” in Sanskrit), he was widely regarded as one of the foremost astrophysicists of the 20th century.

“Chandra continues to be one of the most successful missions that NASA has ever flown as measured against any metric – cost, schedule, technical success and, most of all, scientific discoveries,” said Martin Weisskopf, Chandra Project Scientist at the Marshall Space Flight Center in Huntsville, Ala. “It has been a privilege to work on developing and maintaining this scientific powerhouse, and we look forward to many years to come.”

NASA raised thousands of jellyfish in space.

Posted by

1


I Don’t Think You’re Ready for This, Jelly

NASA raised thousands of jellyfish in space. They ended up unfit for life on Earth.

A moon jelly, illuminated (Hans Hillewaert/Wikimedia Commons)

Since the early 1990s, we humans have been doing something both odd and eminently sensible: We’ve been launching jellyfish into space. And we have been doing so for science. During NASA’s first Spacelab Life Sciences (SLS-1) mission in 1991, NASA began conducting an experiment: “The Effects of Microgravity-Induced Weightlessness on Aurelia Ephyra Differentiation and Statolith Synthesis.” To carry it out, the space shuttle Columbia launched into space a payload of 2,478 jellyfish polyps—creatures contained within flasks and bags that were filled with artificial seawater. Astronauts injected chemicals into those bags that would induce the polyps to swim freely (and, ultimately, reproduce). Over the course of the mission, the creatures proliferated: By mission’s close, there were some 60,000 jellies orbiting Earth.

The point of all this, as the experiment’s title (sort of) suggests, was to test microgravity’s effects on jellyfish as they develop from polyp to medusa. And the point of that, in turn, was to test how the jellyfish would respond when they were back on Earth. Jellyfish, foreign to us in so many ways, are like humans in one very particular manner: They orient themselves according to gravity.

As the biologist RR Helm explains it:

When a jelly grows, it forms calcium sulfate crystals at the margin of its bell. These crystals are surrounded by a little cell pocket, coated in specialized hairs, and these pockets are equally spaced around the bell. When jellies turn, the crystals roll down with gravity to the bottom of the pocket, moving the cell hairs, which in turn send signals to neurons. In this way, jellies are able to sense up and down. All they need is gravity.

Humans, of course, are similarly sensitive. We sense both gravity and and acceleration using otoliths, calcium crystals in our inner ears that move ultra-sensitive hair cells, thus informing our brains which way gravity is pulling us. So if the space-raised jellyfish didn’t fully develop their version of gravity-sensors, the thinking goes, it’s likely that humans raised in microgravity would have similar trouble.

And here, according to Deep Sea News, is the result of the studies: The astro-jellies’ sense of gravity did, indeed, seem to be impaired by being raised in space. The results of the STS-1 experiment, published in the journal Advances in Space Research, noted that while the space-bred jellies were “morphologically very similar to those which developed on Earth,” their motor abilities were different on Earth than they were in microgravity. In a kind of lit review of the jelly experiments, Helm notes that “while development of the sensory pockets appears normal, many more jellies had trouble getting around once on the planet.” The difficulties included, alas, “pulsing and movement abnormalities, compared to their Earth-bound counterparts.”

Basically, the invertebrates had vertigo. (Or, as PopSci puts it: “As cool as being an astronaut baby sounds, the jellies didn’t develop the same gravity-sensing capabilities as their Earthly relatives.”) Which may not bode well for the vertebrate organisms that may be born in microgravity—space-faring humans among them.