On May 9th, the planet Mercury will pass in front of the sun, producing an inky-black spot on the solar disk. Catch it live on the Internet, courtesy of the Coca-Cola Space Science Center in Columbus, Georgia. | | | CHANCE OF STORMS: NOAA forecasters say there is a 65% chance of G1-class geomagnetic storms on May 9th when Earth enters a solar wind stream filled with negative-polarity magnetic fields. A display of high-latitude auroras is possible, especially in the southern hemisphere where visibility is improved by darkening autumn skies. Antarctic photographers, warm up your cameras! Aurora alerts: text, voice. TRANSIT OF MERCURY: On Monday morning, May 9th, Mercury will pass directly between Earth and the sun, producing a rare transit visible from the Americas, Europe, Africa and much of Asia. According to NASA, this is what the tiny black disk of the innermost planet will look like as it crosses the solar disk: In the USA, the transit begins around 7:15 am eastern time. This means it begins before sunrise on the west coast, but that's no problem. The transit lasts for more than 7 hours, so Mercury will still be gliding across the solar disk when the sun comes up over places like California and Alaska. Everyone in the USA can experience the event. Indeed, people on almost every continent can see at least some of the transit. These global visibility maps are courtesy of ShadowandSubstance.com: Now for the bad news: Mercury is so small, you can't see the transit with the unaided eye. Safely-filtered solar telescopes are required. Don't have one? In that case, you can watch the transit online, broadcast live from the Coca-Cola Space Science Center in Columbus, Georgia. Also, NASA's Solar Dynamics Observatory will transmit images from space. Mercury passes directly between the sun and Earth about 13 times every century. The last time it happened was ten years ago in 2006, meaning it is more rare than lunar and solar eclipses. If you miss Monday's transit, you'll have to wait until Nov.11, 2019, for the next one. Realtime Space Weather Photo Gallery A FLOWER IN A DROPLET OF WATER: Photographers, the next time you want to take a great picture of a flower, don't point your lens at the bloom. Point it at the raindrops clinging to the stem. Mila Zinkova of San Francisco followed this procedure after a rainstorm on May 6th, and here is result: "Raindrops provide some interesting photo opportunities because they act as inverting lenses," says Zinkova. "Images inside appear upside down." A few weeks ago, Zinkova discovered you can fit an entire suspension bridge inside a raindrop. This photo captures the Golden Gate Bridge multiplied through the rain-splattered windshield of her car. "The fly in that image is not seen through a droplet, and thats why its orientation is normal," she explains. Realtime Space Weather Photo Gallery Realtime Sprite Photo Gallery Realtime Aurora Photo Gallery Realtime Comet 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 May. 7, 2016, the network reported 30 fireballs. (18 sporadics, 12 eta Aquariids) 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 May 7, 2016 there were potentially hazardous asteroids. 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. | Cosmic Rays in the Atmosphere | Situation Report -- Oct. 30, 2015 | Stratospheric Radiation (+37o N) | Cosmic ray levels are elevated (+6.1% above the Space Age median). The trend is flat. Cosmic ray levels have increased +0% in the past month. | Sept. 06: 4.14 uSv/hr (414 uRad/hr) | Sept. 12: 4.09 uSv/hr (409 uRad/hr) | Sept. 23: 4.12 uSv/hr (412 uRad/hr) | Sept. 25: 4.16 uSv/hr (416 uRad/hr) | Sept. 27: 4.13 uSv/hr (413 uRad/hr) | Oct. 11: 4.02 uSv/hr (402 uRad/hr) | Oct. 22: 4.11 uSv/hr (411 uRad/hr) | These measurements are based on regular space weather balloon flights: learn more. Approximately once a week, Spaceweather.com and the students of Earth to Sky Calculus fly "space weather balloons" to the stratosphere over California. These balloons are equipped with radiation sensors that detect cosmic rays, a surprisingly "down to Earth" form of space weather. Cosmic rays can seed clouds, trigger lightning, and penetrate commercial airplanes. Our measurements show that someone flying back and forth across the continental USA, just once, can absorb as much ionizing radiation as 2 to 5 dental X-rays. For example, here is the data from a flight on Oct. 22, 2015: Radiation levels peak at the entrance to the stratosphere in a broad region called the "Pfotzer Maximum." This peak is named after physicist George Pfotzer who discovered it using balloons and Geiger tubes in the 1930s. Radiation levels there are more than 80x sea level. Note that the bottom of the Pfotzer Maximim is near 55,000 ft. This means that some high-flying aircraft are not far from the zone of maximum radiation. Indeed, according to the Oct 22th measurements, a plane flying at 45,000 feet is exposed to 2.79 uSv/hr. At that rate, a passenger would absorb about one dental X-ray's worth of radiation in about 5 hours. The radiation sensors onboard our helium balloons detect X-rays and gamma-rays in the energy range 10 keV to 20 MeV. These energies span the range of medical X-ray machines and airport security scanners. | 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 | |