Category Archives: Astronomy

Kepler diagram

NASA Kepler Recovery Continues, Wheel Two Shows Hope.

The primary tool in the search for exo-Earths may return to service. Recently the second of four reaction wheels failed on the Kepler Telescope. At least three wheels are needed…

August 5, 2013: Something big is about to happen on the sun. According to measurements from NASA-supported observatories, the sun's vast magnetic field is about to flip. "It looks like we're no more than 3 to 4 months away from a complete field reversal," says solar physicist Todd Hoeksema of Stanford University. "This change will have ripple effects throughout the solar system." Field Flip (splash) A new ScienceCast video anticipates the reversal of the sun's global magnetic field. Play it The sun's magnetic field changes polarity approximately every 11 years. It happens at the peak of each solar cycle as the sun's inner magnetic dynamo re-organizes itself. The coming reversal will mark the midpoint of Solar Cycle 24. Half of 'Solar Max' will be behind us, with half yet to come. Hoeksema is the director of Stanford's Wilcox Solar Observatory, one of the few observatories in the world that monitor the sun's polar magnetic fields. The poles are a herald of change. Just as Earth scientists watch our planet's polar regions for signs of climate change, solar physicists do the same thing for the sun. Magnetograms at Wilcox have been tracking the sun's polar magnetism since 1976, and they have recorded three grand reversals—with a fourth in the offing. Field Flip (WSO, 200px) Astronomers at the Wilcox Solar Observatory (WSO) monitor the sun's global magnetic field on a daily basis. WSO home page Solar physicist Phil Scherrer, also at Stanford, describes what happens: "The sun's polar magnetic fields weaken, go to zero, and then emerge again with the opposite polarity. This is a regular part of the solar cycle." A reversal of the sun's magnetic field is, literally, a big event. The domain of the sun's magnetic influence (also known as the "heliosphere") extends billions of kilometers beyond Pluto. Changes to the field's polarity ripple all the way out to the Voyager probes, on the doorstep of interstellar space. When solar physicists talk about solar field reversals, their conversation often centers on the "current sheet." The current sheet is a sprawling surface jutting outward from the sun's equator where the sun's slowly-rotating magnetic field induces an electrical current. The current itself is small, only one ten-billionth of an amp per square meter (0.0000000001 amps/m2), but there’s a lot of it: the amperage flows through a region 10,000 km thick and billions of kilometers wide. Electrically speaking, the entire heliosphere is organized around this enormous sheet. During field reversals, the current sheet becomes very wavy. Scherrer likens the undulations to the seams on a baseball. As Earth orbits the sun, we dip in and out of the current sheet. Transitions from one side to another can stir up stormy space weather around our planet. Field Flip (current sheet, 200px) An artist's concept of the heliospheric current sheet, which becomes more wavy when the sun's magnetic field flips. More Cosmic rays are also affected. These are high-energy particles accelerated to nearly light speed by supernova explosions and other violent events in the galaxy. Cosmic rays are a danger to astronauts and space probes, and some researchers say they might affect the cloudiness and climate of Earth. The current sheet acts as a barrier to cosmic rays, deflecting them as they attempt to penetrate the inner solar system. A wavy, crinkly sheet acts as a better shield against these energetic particles from deep space. As the field reversal approaches, data from Wilcox show that the sun's two hemispheres are out of synch. "The sun's north pole has already changed sign, while the south pole is racing to catch up," says Scherrer. "Soon, however, both poles will be reversed, and the second half of Solar Max will be underway."

Magnetic Poles of Sun about to flip, Solar Max Near

(NASA) According to recent measurements the magnetic field of the Sun is about to change indicating were very near the Solar Max. “It looks like we’re no more than 3…

Gamma Ray Burst 130603B

Hubble Sees Fireball After Gamma Ray Burst

(NASA) – The Hubble Space Telescope recently provided the strongest evidence yet that short-duration gamma ray bursts are produced by the merger of two small, super-dense stellar objects. The evidence…

SDO IRIS compare

New IRIS Space Telescope Shows Sun Up Close

The IRIS Telescope was launched from Vandenberg Air Force Base, Calif., on June 27, 2013 on a mission to study the lower interface regions of the suns atmosphere. The telescope opened…

Comet ISON

New Image of Comet ISON from Hubble

The sun-approaching Comet ISON floats against a seemingly infinite backdrop of numerous galaxies and a handful of foreground stars. The icy visitor, with its long gossamer tail, appears to be…

Kepler Telescope

Planet Hunter Kepler Starts Tests on Road to Recovery

The most prolific planet hunter in history recently suffered a serious blow when the second of four reaction wheels failed and it could no longer steer itself and take science…

Earth from Saturn

New Images of Earth from Cassini at Saturn

We reported on June 18th that NASA had planned to take images of Earth from Cassini as it orbits Saturn, well here are the pictures. NASA’s Cassini spacecraft took the…

new neptune moon

NASA’S HUBBLE FINDS NEW NEPTUNE MOON

(Source NASA) -Hubble Space Telescope has discovered a new moon orbiting the distant blue-green planet Neptune, the 14th known to be circling the giant planet. The moon, designated S/2004 N…