A white dwarf star that has morphed into a massive pulsing crystal.
A white dwarf star that has morphed into a massive pulsing crystal.
Tag: astronomy
After ten years of operation, NASA has turned off its Galaxy Evolution Explorer (GALEX) space telescope.
After ten years of operation, NASA has turned off its Galaxy Evolution Explorer (GALEX) space telescope.
In a first-of-a-kind move for NASA, the agency in May 2012 loaned GALEX to the California Institute of Technology in Pasadena, which used private funds to continue operating the satellite while NASA retained ownership. Since then, investigators from around the world have used GALEX to study everything from stars in our own Milky Way galaxy to hundreds of thousands of galaxies 5 billion light-years away.
It appears this loan arrangement has now ended because of a lack of funds. Either way, it always baffles me when NASA shuts down a working science telescope merely because it has been operating for a long time. Eventually the space agency will call for a replacement, the building of which will be far more expensive than it would have been to keep the original in operation.
Voyager 1 has found the edge of the solar system to be far more complex than predicted by scientists.
The uncertainty of science: Voyager 1 has found the edge of the solar system to be far more complex than predicted by scientists.
Scientists had assumed that Voyager 1, launched in 1977, would have exited the solar system by now. That would mean crossing the heliopause and leaving behind the vast bubble known as the heliosphere, which is characterized by particles flung by the sun and by a powerful magnetic field.
The scientists’ assumption turned out to be half-right. On Aug. 25, Voyager 1 saw a sharp drop-off in the solar particles, also known as the solar wind. At the same time, there was a spike in galactic particles coming from all points of the compass. But the sun’s magnetic field still registers, somewhat diminished, on the spacecraft’s magnetometer. So it’s still in the sun’s magnetic embrace, in a sense.
Orbital Sciences’ Pegasus rocket this evening successfully launched NASA’s newest solar research satellite, the Interface Region Imaging Spectrograph (IRIS).
Orbital Sciences’ Pegasus rocket this evening successfully launched NASA’s newest solar research satellite, the Interface Region Imaging Spectrograph (IRIS).
Kepler’s planet-hunting predecessor, COROT, has been shut down.
Kepler’s planet-hunting predecessor, CoRoT, has been shut down.
CoRoT suffered a computer failure on November, 2, 2012 and although the spacecraft is capable of receiving navigational commands, the French Space Agency CNES reports it can no longer retrieve data from its 30-centimeter telescope. After a valiant effort to try and restore the computer, CNES announced this week that the spacecraft has been retired. CoRoT’s journey will come to a fiery end as it will be deorbited and it will burn up on re-entry in Earth’s atmosphere.
CoRoT found 32 exoplanets with at least a hundred more candidates still to be confirmed.
The remarkable remains of a most recent supernova.
The remarkable remains of a most recent supernova.
Astronomers estimate that a star explodes as a supernova in our Galaxy, on average, about twice per century. In 2008, a team of scientists announced they discovered the remains of a supernova that is the most recent, in Earth’s time frame, known to have occurred in the Milky Way. The explosion would have been visible from Earth a little more than a hundred years ago if it had not been heavily obscured by dust and gas. Its likely location is about 28,000 light years from Earth near the center of the Milky Way.
Astronomers have found a solar system with six exoplanets, three in the habitable zone.
Worlds without end: Astronomers have found a solar system with six exoplanets, three in the habitable zone.
These planets orbit the third fainter star of a triple star system. Viewed from one of these newly found planets the two other suns would look like a pair of very bright stars visible in the daytime and at night they would provide as much illumination as the full Moon. The new planets completely fill up the habitable zone of Gliese 667C, as there are no more stable orbits in which a planet could exist at the right distance to it.
The planets in the habitable zone are all super-Earths.
Update: you can download and read the science paper here.
The count of candidate exoplanets found by Kepler has now risen another 503 to 3,216, of which only 132 have been confirmed.
The count of candidate exoplanets found by Kepler has now risen another 503 to 3,216, of which only 132 have been confirmed.
These new exoplanets were found before the telescope failed but the data for them is only now being released.
NASA has decided that the best use for two space mirrors donated to the space agency by the National Reconnaissance Office (NRO) would be to study either dark energy and extrasolar planets.
NASA has decided that the best use for two space mirrors donated to the space agency by the National Reconnaissance Office (NRO) would be to study either dark energy and extrasolar planets.
There is no funding as yet for either mission, so for the moment the mirrors will remain on the ground, in storage.
German scientists have outlined a technique for using pulsars as an interplanetary and interstellar GPS system.
German scientists have outlined a technique for using pulsars as an interplanetary and interstellar GPS system.
Astronomers take an image of an exoplanet only 300 light years away.
Astronomers take an image of an exoplanet only 300 light years away.
Radar images of asteroid 1998 QE2, flying past the Earth today, show that it has its own moon.
Radar images of asteroid 1998 QE2, flying past the Earth today, show that it has its own moon.
When astronomers analyzed radar readings to create their first maps of 1998 QE2, the big asteroid that’s due to sail past Earth on Friday, they were surprised to find that it has a moon twice as big as an ocean liner. 1998 QE2 itself is way bigger: The latest readings from NASA’s Deep Space Network antenna in Goldstone, Calif., are consistent with earlier estimates that the asteroid is about 1.7 miles (2.7 kilometers wide). But the moon is hefty as well. Astronomers estimate its diameter at 2,000 feet (600 meters).
Cassini has found hints of activity coming from the Saturn moon Dione.
Cassini has found hints of activity coming from the Saturn moon Dione.
The spacecraft’s magnetometer has detected a faint particle stream coming from the moon, and images showed evidence for a possible liquid or slushy layer under its rock-hard ice crust. Other Cassini images have also revealed ancient, inactive fractures at Dione similar to those seen at Enceladus that currently spray water ice and organic particles.
Not only can the very fast rotation of neutron stars sometimes speed up suddenly, scientists have now discovered that their rotation can suddenly slow as well.
Not only can the very fast rotation of neutron stars sometimes speed up suddenly, scientists have now discovered that their rotation can suddenly slow as well.
The neutron star, 1E 2259+586, is located about 10,000 light-years away toward the constellation Cassiopeia. It is one of about two dozen neutron stars called magnetars, which have very powerful magnetic fields and occasionally produce high-energy explosions or pulses. Observations of X-ray pulses from 1E 2259+586 from July 2011 through mid-April 2012 indicated the magnetar’s rotation was gradually slowing from once every seven seconds, or about eight revolutions per minute. On April 28, 2012, data showed the spin rate had decreased abruptly, by 2.2 millionths of a second, and the magnetar was spinning down at a faster rate.
Astronomers had a theory which explained the sudden increase in a neutron star’s rotation. They don’t have one yet for why this star slowed.
Dark matter, WIMPS, and NASA’s Alpha Magnetic Spectrometer
Dark matter, WIMPS, and NASA’s Alpha Magnetic Spectrometer
This very nicely written article describing the scientific goals of AMS is even better in that it emphasizes strongly the uncertainties of the data and the theories behind it.
Scientists have released the first topo map of Titan.
Scientists have released the first topo map of Titan.
Whereas Earth’s tallest mountain towers nearly 9 kilometers above sea level, Titan’s topographic variations are mild: Its highest point is just half a kilometer above the mean and its lowest just 1.7 kilometers below.
Overall the detail here is not very great. None of the instruments on Cassini can see anything smaller than a half kilometer, about 1,500 feet, so the data doesn’t really show us the rough details. Moreover, the best data is spotty, as it has been accumulated by about a hundred Cassini fly-bys, rather than systematically by an orbiting spacecraft.
The impact of a 100 pound meteorite on the Moon in March produced the brightest flash ever recorded.
The impact of a 100 pound meteorite on the Moon in March produced the brightest flash ever recorded.
Anyone looking at the Moon at the moment of impact could have seen the explosion–no telescope required. For about one second, the impact site was glowing like a 4th magnitude star.
Ron Suggs, an analyst at the Marshall Space Flight Center, was the first to notice the impact in a digital video recorded by one of the monitoring program’s 14-inch telescopes. “It jumped right out at me, it was so bright,” he recalls.
The 40 kg meteoroid measuring 0.3 to 0.4 meters wide hit the Moon traveling 56,000 mph. The resulting explosion1 packed as much punch as 5 tons of TNT.
It will be really interesting to see the Lunar Reconnaissance Orbiter images of the impact site, which can’t be taken until the spacecraft passes over the site and can photograph it.
The Kepler mission has lost its second gyroscope, ending the ability of the telescope to aim precisely.
The Kepler mission has lost its second gyroscope, ending the ability of the telescope to aim precisely. More details here.
The telescope’s primary mission, to stare continuously at one section of sky, looking for exoplanet transits, is over, though it might still be re-purposed for other astronomical research.
Last Saturday the space telescope Swift detected the most powerful gamma ray bursts ever detected.
Last Saturday the space telescope Swift detected the most powerful gamma ray burst ever detected.
You can see the raw reports of the detection, followed up immediately by a host of other ground-based and space-based observations at this website. Click on the circulars for GRB130427A, starting with circular 14448. When this happened last Saturday I was out camping. When I got home there were dozens of circulars to look at. Based on the data here, this gamma-ray burst was relatively close for a grb, approximately 3.6 billion light years away.
The lingering echo of Comet Shoemaker-Levy in the atmosphere of Jupiter.
The lingering echo of Comet Shoemaker-Levy in the atmosphere of Jupiter.
The Herschel observations, together with heat maps provided by NASA’s Infrared Telescope Facility on Mauna Kea, showed the researchers that the Jovian stratosphere was 20° to 30°F (10° to 15°C) warmer than it would be if completely dry. One question is whether the stratospheric warming results from the gentle, continuous infall of interplanetary dust particles, which would be warmed by sunlight as they linger high up. Cavalié and his colleagues believe IDPs create some of the infrared emission but cannot explain it all. Further, a continuously supplied source would migrate to lower depths, yet most of the emission is too high up, at pressures less than 2 millibars. And while the amount of water is roughly constant across the southern hemisphere, the emission gradually weakens northward until it’s less than half as strong. It’s not simply that Jupiter’s bottom half is hotter — there’s just more water down there. As the researchers note, “At least 95% of the observed water comes from the SL9 comet and subsequent (photo)-chemistry in Jupiter’s stratosphere according to our models, as of today.
Taken together, they conclude, these observations offer “clear evidence that a recent comet … is the principal source of water in Jupiter. What we observe today is a remnant of the oxygen delivery by the comet at 44°S in July 1994.”