When is the best time to see auroras? Where is the best place to go? And how do you photograph them? These questions and more are answered in a new book, Northern Lights - a Guide, by Pal Brekke & Fredrik Broms. | | |
CHANCE OF FLARES: NOAA forecasters estimate a 60% chance of M-class flares and a 30% chance of X-flares on June 12th. The likely shource is sunspot AR2087, which has already produced three major eruptions since June 10th and is turning toward Earth. Solar flare alerts: text, voice
MARS ROVER SEES SOLAR TRANSIT: Last week NASA's Curiosity rover witnessed something no one has ever seen from the surface of another world: a planetary transit of the sun. As the sun rose over Mars' Gale Crater on June 3rd, Curiosity's two-eyed MastCam tracked the shadowy silhouette of Mercury crossing the solar disk:
In addition to showing Mercury, the same MastCam frames show two sunspots approximately the size of Earth.
This is the first transit of the sun by a planet observed from any planet other than Earth, and also the first imaging of Mercury from Mars. Mercury fills only about one-sixth of one pixel as seen from such a great distance, so the darkening does not have a distinct shape. Nevertheless, it is definitely Mercury as the shadow follows Mercury's expected path based on orbital calculations.
On Earth, it is possible to observe solar transits of Mercury and Venus, although they are rare. Last seen in June 2012, Venus transits are typically separated by more than a hundred years. The next Mercury transit visible from Earth will be May 9, 2016. Mercury and Venus transits are visible more often from Mars than from Earth, and Mars also offers a vantage point for seeing Earth transits. The next of each type visible from Mars will be Mercury in April 2015, Venus in August 2030 and Earth in November 2084.
INCOMING CME: The double X-flare of June 10th may have produced a geoeffective CME after all. At first it appeared that Earth was outside the line of fire, but a closer look at the CME reveals an Earth-directed component. Click to view a movie of the explosion from the Solar and Heliospheric Observatory:
The movie shows a faint CME associated with the first X-flare emerging around 1200 UT. A second, brighter CME from the second X-flare quickly overtakes it, forming a "cannibal CME." Computer models run yesterday by NOAA analysts suggest the merged storm cloud will reach Earth mid-day on June 13th. The glancing blow could spark polar geomagnetic storms.
Meanwhile, more X-flares are in the offing. At least two sunspots (AR2080 and AR2087) have unstable 'delta-class' magnetic fields that could erupt at any moment. The source of yesterday's X-flares, AR2087, is particularly potent, and it is turning toward Earth. NOAA forecasters estimate a 60% chance of M-flares and a 30% chance of X-flares on June 11th. Solar flare alerts: text, voice
Realtime Space Weather Photo Gallery
HALOBACTERIA SET A NEW HIGH-ALTITUDE RECORD: Astrobiologsts have long wondered if halobacteria, a terrestrial extremophile with a special talent for shielding itself from UV radiation, could survive on the planet Mars. To find the answer, the students of Earth to Sky Calculus have been flying halobacteria onboard balloons to the top of Earth's atmosphere. During their latest flight on June 7th, the microbes set a high-altitude record for their species. Here they are 116,524 feet above the Sierras of central California:
The previous record set by the students just last month was 112,000 feet, so this was nearly a mile higher than before.
During the June 7th flight, onboard sensors registered temperatures as low as -60 C, air pressures of 1% sea level, and cosmic radiation levels 25 times Earth-normal. Those are conditions akin to the planet Mars. Three hours after they were launched, the bacteria landed in the Death Valley National Park: snapshot. This means they experienced a 100 C swing in temperature, a 100-fold change in air pressure, and a 25-fold surge of radiation.
The students have already shown that halobacteria can survive trips like this. Now they are working to determine survival rates, growth curves, and to look at possible mutations among the halo-survivors. Results could contribute to an important body of knowledge about the prospects for life on Mars -- past, present, and future.
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Realtime Meteor Photo Gallery
Every night, a network of NASA all-sky cameras scans the skies above the United States for meteoritic fireballs. Automated software maintained by NASA's Meteoroid Environment Office calculates their orbits, velocity, penetration depth in Earth's atmosphere and many other characteristics. Daily results are presented here on Spaceweather.com.
On Jun. 12, 2014, the network reported 7 fireballs.
( 7 sporadics)
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). [Larger image] [movies]
Potentially Hazardous Asteroids (
PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding
new ones all the time.
On June 12, 2014 there were 1485 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters: Asteroid | Date(UT) | Miss Distance | Size |
2011 PU1 | Jul 18 | 7.6 LD | 43 m |
2002 JN97 | Aug 2 | 61.4 LD | 2.0 km |
2001 RZ11 | Aug 17 | 34.2 LD | 2.2 km |
2013 WT67 | Aug 17 | 16.1 LD | 1.2 km |
Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach. | The official U.S. government space weather bureau |
| The first place to look for information about sundogs, pillars, rainbows and related phenomena. |
| Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever. |
| 3D views of the sun from NASA's Solar and Terrestrial Relations Observatory |
| Realtime and archival images of the Sun from SOHO. |
| from the NOAA Space Environment Center |
| the underlying science of space weather |