NASA’s Planet-Hunting Kepler Telescope Will Have Long Legacy, Despite Big Glitch
Whether or not NASA’s Kepler spacecraft can bounce back from the malfunction that has stalled its search for alien planets, the mission’s place in history is assured, scientists say.
Kepler has spotted more than 2,700 potential exoplanets to date, with many more waiting to be plucked from the mission’s huge dataset. Its discoveries have opened the eyes of scientists and the public alike, revealing that the Milky Way galaxy abounds with an incredible diversity of alien worlds.
“Kepler has opened up the next set of questions in exoplanets,” Paul Hertz, astrophysics director at NASA Headquarters in Washington, D.C., told reporters Wednesday (May 15).
“Before we flew Kepler, we didn’t know that Earth-sized planets in habitable zones were common throughout our galaxy,” Hertz added. “We didn’t know that virtually every star in the sky had planets around them. Now we know that.”
An uncertain future
The Kepler spacecraft launched in March 2009, kicking off a 3.5-year prime mission to determine how common Earth-like planets are throughout the galaxy.
The observatory spots alien worlds by detecting the tiny brightness dips caused when they pass in front of their parent stars from the instrument’s perspective. To stay locked onto its 150,000-plus target stars, Kepler needs three functioning reaction wheels, gyroscope-like devices that allow the spacecraft to maintain its position in space.
Kepler has four such wheels. But one, known as No. 2, failed in July 2012. And No. 4 has now failed as well, NASA officials announced Wednesday.
Mission engineers will try to bring the twofailed wheels back into serviceover the coming weeks. If they cannot recover at least one wheel, Kepler’s planet-hunting days are almost certainly over, though the observatory may get a new mission that doesn’t require incredibly precise pointing.
Mapping out a new mission would likely take months, Hertz said.
“It’s a technical study that the project needs to do to identify what the options are,” he said. “And then we would have to do a scientific study to determine what the benefits of those options might be.”
Revolutionizing exoplanet science
While just 132 of Kepler’s 2,700 exoplanet candidates have been confirmed to date, mission scientists expect that more than 90 percent will turn out to be the real deal. And the team has had time to go through just half of the spacecraft’s dataset thus far, team members said.
“We have excellent data for an additional two years,” said Kepler principal investigator Bill Borucki, of NASA’s Ames Research Center in Moffett Field, Calif. “So I think the most interesting, exciting discoveries are coming in the next two years.”
One such find might be the first true “alien Earth,” a potentially life-supporting planet the size of our own. Kepler has already spotted several possibly habitable worlds, including the recently announced Kepler-62e and Kepler-62f, but all of them are slightly larger than Earth.
Future discoveries will be icing on the cake, experts say. Kepler has already revolutionized exoplanet science, giving researchers an unprecedented systematic look at worlds beyond our solar system.
“The science returns of the Kepler mission have been staggering and have changed our view of the universe, in that we now think there are planets just about everywhere,” Scott Hubbard of Stanford University said in a statement. (Hubbard, a former NASA “Mars czar,” served as director of NASA Ames during much of Kepler’s development.)
For example, astronomers recently used Kepler data to estimate that 6 percent of the galaxy’s 75 billion red dwarfs — stars smaller and dimmer than the sun — likely host habitable, roughly Earth-size planets. That works out to a minimum of 4.5 billion alien Earths, the closest of which may be just 13 light-years away, according to the study.
Kepler observations have further revealed that small, rocky worlds like our own are much more common throughout the Milky Way than gas giants such as Saturn or Jupiter, at least in relatively close-in orbits.
“It really goes back to, at least for me personally, sitting on my rooftop watching the stars, thinking about what’s out there,” said NASA science chief John Grunsfeld, a former space shuttle astronaut. “And now we know, because of Kepler and the hard work of all the Kepler scientists.”
If light has no mass how can it be affected by gravity?
Because it has momentum
But momentum is mass x velocity so how can it have momentum?
Because language can sometimes bring more problems than answers. Light does not obey the same laws as ordinary matter. To help…
All mammals sleep, as do birds and some insects. However, how this basic function is regulated by the brain remains unclear. According to a new study by researchers from the RIKEN Brain Science Institute, a brain region called the lateral habenula plays a central role in the regulation of REM sleep. In an article published today in the Journal of Neuroscience, the team shows that the lateral habenula maintains and regulates REM sleep in rats through regulation of the serotonin system. This study is the first to show a role of the lateral habenula in linking serotonin metabolism and sleep.
The lateral habenula is a region of the brain known to regulate the metabolism of the neurotransmitter serotonin in the brain and to play a key role in cognitive functions.
“Serotonin plays a central role in the pathophysiology of depression, however, it is not clear how abnormalities in regulation of serotonin metabolism in the brain lead to symptoms such as insomnia in depression,” explain Dr. Hidenori Aizawa and Dr. Hitoshi Okamoto who led the study.
Since animals with increased serotonergic activity at the synapse experienced less REM sleep, the researchers hypothesized that the lateral habenula, which regulates serotonergic activity in the brain, must modulate the duration of REM sleep.
They show that removing the lateral habenula in rats results in a reduction of theta rhythm, an oscillatory activity that appears during REM sleep, in the hippocampus, and shortens the rats’ REM sleep periods. However, this inhibitory effect of the lateral habenular lesion on REM sleep disappears when the serotonergic neurons in the midbrain are lesioned.
The team recorded neural activity simultaneously in the lateral habenula and hippocampus in a sleeping rat. They find that the lateral habenular neurons, which fire persistently during non-REM sleep, begin to fire rhythmically in accordance with the theta rhythm in the hippocampus when the animal is in REM sleep.
“Our results indicate that the lateral habenula is essential for maintaining theta rhythms in the hippocampus, which characterize REM sleep in the rat, and that this is done via serotonergic modulation,” concludes Dr Aizawa.
“This study reveals a novel role of the lateral habenula, linking serotonin and REM sleep, which suggests that an hyperactive habenula in patients with depression may cause altered REM sleep,” add the authors.
The Square Kilometer Array
A name soon to be added to the lexicon of every astro-junkie out there. Perhaps the most audacious international telescope project ever conceptualized.
As of May 7, 2013, less than a year after the decision to site the Square Kilometer Array(SKA) in both Southern Africa and Australia, the SKA Organization has opened its new international headquarters in Jodrell Bank Observatory, UK. This entire project has been a collaborative effort from a number of different countries: South Africa, Australia, Sweden, Canada, China, Italy, The Netherlands, Germany, and New Zealand. In light of this, let us “tune in” to some interesting facts of the (soon-to-be) world’s largest radio telescope.
This telescope is actually a network of thousands of radio telescopes that span across thousands of kilometers in two desert locations in Australia and in South Africa. These form what is called an “astronomical interferometer.” The harsh desert locations have been carefully chosen because of their remoteness from any possible man made radio interference.
The telescopes are linked together by powerful supercomputers to create one immense, radio telescope with a collecting area totaling about one square kilometer (hence the name). This equates to one million square meters (or 140 football fields) to collect the faintest of radio waves spanning from the very furthest reaches of the universe.
Poised to answer the biggest questions of astronomy, like the origin and evolution of the universe, it will investigate the first galaxies formed after the big bang. It is 50 times more powerful than any radio telescope we have ever created, and it has better resolution than the Hubble. The SKA will be able to collect data on vast swaths of the sky, and at a speed 10 000 times faster than current survey telescopes. If fact, it is so sensitive that it would be able to detect airport radar on another planet 50 LIGHT YEARS away.
It will provide the highest resolution images in astronomy; it will require high powered computer servers greater than the current global internet needs. The SKA central computer will have the processing power of about one hundred million PCs. This is truly high-performance computing; in one month, it will generate more information than is contained in the world’s academic libraries.
Image source: http://www.redorbit.com/media/uploads/2012/12/SKA-617x416.jpg
We never sit here under the weight of all this air, the 5 x 10^18 kg of atmosphere that sits above everyone on Earth, and say “Gosh, that sure is heavy!”
You don’t realize just how powerful that 1 bar (~100 kPa) of pressure is until a train car is filled with steam, allowed to cool, and then implodes ohmygod did that just happen?
For more implosion goodness, check out this awesome video from Veritasium.
Goodbye to Rhea
On its fourth and final targeted flyby of Rhea, the Cassini spacecraft provided this stunning view of the ancient and heavily cratered surface. Billions of years of impacts have sculpted Rhea’s surface into the form we see today. With a diameter of 949 miles (1,528 kilometers) Rhea is Saturn’s second-largest moon.
Image credit: NASA/JPL-Caltech/Space Science Institute