Astro Bob 24 Feb 2018, 19:22 UTC Viewers in the northern states may have a brush with the aurora tomorrow night (Feb. 25). A minor G1 storm is expected from around 9 p.m. to midnight Central time. Hopefully, the half-moon won’t be shiny enough to erase the arcs or rays we might see. The aurora takes many forms. Quiet arcs, bands that break into minions of bright rays, the coronal crown and pulsating patches. The last will be familiar to anyone who’s stuck long enough to watch a bright aurora subside into flashing or blinking patches of light. They throb in and out of view across the northern sky with the rhythm of an irregular heartbeat with periods that range from several to 10 seconds. Called pulsating aurora, they’re more common late at night or before the start of dawn. Easy to see, they’re hard to photograph because they move flash quickly and end up looking like static glows in time exposures. Experiencing them live or through video is the way to go.
Planetaria 24 Feb 2018, 03:22 UTC I missed posting this before, but there are some very interesting updates about the TRAPPIST-1 exoplanets (seven Earth-sized planets orbiting a red dwarf star 40 light-years away). There are two new science papers, which indicate that all seven could have water in some form, ranging from vapour to liquid to ice, depending on their distance from the star and other factors. Some of the planets could have up to 5% of their mass composed of water, compared to 0.02% for Earth! Some probably have thick atmospheres while others have thinner atmospheres.
Lights in the Dark 23 Feb 2018, 18:48 UTC Can you feel the heat? NASA’s Mars Odyssey can see it! This is an image of Mars’ smaller moon Deimos, captured with Odyssey’s THEMIS (Thermal Emission Imaging System) instrument on Feb. 15, 2018. Part of the 7-mile-wide Moon was in shadow, but the sunlit surface area reached temperatures up to 200 K (that’s still pretty cold for us, though… –100ºF / -73ºC!)
Centauri Dreams 23 Feb 2018, 13:44 UTC The Kepler space telescope has established that exoplanets are abundant in our galaxy and that many stars have planets in their habitable zones (defined as having temperatures that potentially allow surface water). This has reinvigorated the quest to answer the age-old question “Are We Alone?”. While SETI attempts to answer that question by detecting intelligent signals, the Drake equation suggests that the emergence of intelligence is a subset of the planets where life has emerged. When we envisage such living worlds, the image that is often evoked is of a verdant paradise, with abundant plant life clothing the land and emitting oxygen to support respiring animals, much like our pre-space age visions of Venus.
Geekwire 22 Feb 2018, 20:49 UTC The 1,000-foot Arecibo radio telescope in Puerto Rico, made famous by such movies as “Contact” and the James Bond thriller “Goldeneye,” will be under new management. Today the National Science Foundation announced that the University of Central Florida has begun the transition process for taking on operation and management of the observatory. “NSF is currently negotiating the operations and management award with UCF,” the federal agency said in a statement.
Centauri Dreams 22 Feb 2018, 19:40 UTC Between Kepler and the ensuing K2 mission, we’ve had quite a haul of exoplanets. Kepler data have been used to confirm 2341 exoplanets, with NASA declaring 30 of these as being less than twice Earth-size and in the habitable zone. K2 has landed 307 confirmed worlds of its own. K2 offers a different viewing strategy than Kepler’s fixed view of over 150,000 stars. While the transit method is still at work, K2 pursues a series of observing campaigns, its fields of view distributed around the ecliptic plane, and with photometric precision approaching the original.
The Planetary Society Blog 22 Feb 2018, 16:35 UTC Imagine, for a moment, that the sun unleashes the strongest solar flare humanity has ever seen. Then, a coronal mass ejection (CME) event follows, releasing a high-velocity stream of magnetized plasma that slams into the Earth’s protective magnetosphere. The resulting shockwaves propagate through the near Earth-space environment, jolting communications satellites, low-Earth orbit (LEO) satellites, global positioning system (GPS) satellites, and the International Space Station. Radio communications cease, electrical transmission lines fail on the Earth’s surface, and the world fades to black. This is, of course, an extreme scenario—we are unlikely to experience an apocalyptic global blackout, even with the strongest solar flare. Yet, the idea that flares and CMEs can disrupt human activity on Earth and space is not fiction, and it does happen with significant frequency. Any electric circuit in space is vulnerable to CMEs of measurable magnitude, which means it is in society’s best interest to understand how this kind of “weather in space” affects those circuits, namely those belonging to satellites. We increasingly depend on communications and imaging satellites to tell us where we are, guide us to new places, and show us what kind of thunder storms are headed our way. To begin understanding space weather, ...
SPACE.com 22 Feb 2018, 11:31 UTC Last fall, a cucumber-shaped visitor zoomed through the inner solar system. Known as 1I/2017 U1 'Oumuamua, the unusual object sped around the sun before disappearing to the outskirts of the solar system, on its way back to interstellar space.
Space Fellowship 22 Feb 2018, 07:17 UTC Not all roses are red of course, but they can still be very pretty. Likewise, the beautiful Rosette Nebula and other star forming regions are often shown in astronomical images with a predominately red hue, in part because the dominant emission in the nebula is from hydrogen atoms. Hydrogen’s strongest optical emission line, known as H-alpha, is in the red region of the spectrum, but the beauty of an emission nebula need not be appreciated in red light alone.