First, the breaking news. There's a strong possibility of a G2 moderate geomagnetic storm tonight, Sept. 1. I realize that recent aurora forecasts haven't exactly panned out. As always, nature will do what it does without malice or intent. Our job is to remain hopeful.
Forecasters predict tonight's display to kick in around nightfall and linger past midnight. Pinning the aurora to a particular time is ever tricky, but most displays peak between about 10:30 p.m. and 1 a.m. If I see it sooner here from my wooded redoubt here in Duluth, Minn. I'll post an update on Twitter (@AstroBob_bk) and Facebook.
In addition to the aurora alert, I wanted to share this amazing and beautiful image taken by the Hubble Space Telescope. Isn't it one of the most perfect cosmic rings you've ever laid eyes on? Look closely and you'll see two closely-spaced, bright galaxies encircled by a ring and four sparkling points of light. There's also a fifth point at the very center visible in the cropped and enlarged photo below.
What we're seeing is the bizarre phenomenon predicted by Einstein in 1936 called gravitational lensing. The two foreground galaxies are massive objects that together exert a powerful gravitational pull. Einstein predicted that strong gravity fields would warp the fabric of space and bend light — precisely what this dynamic duo is doing.
The four bright points around the galaxies, including the fainter one at center, are really five separate images of a single star-like quasar called 2M1310-1714, located in the far distance behind the pair. When light from a distant object travels through that gravitationally warped space, it's so strongly bent and magnified that multiple images of the quasar result.
Oftentimes, these distant objects are invisible from Earth, but gravitational lensing can brighten them into visibility while also creating odd, kaleidoscopic effects like double, triple and multiple images.
What's a quasar, you're wondering? Actually, it's more of a process than an object. Quasars are typically found in the centers of extremely remote galaxies, where gas spiraling into a supermassive black hole gives off tremendous amounts of energy. All this energy comes from a very small region of space which is why a quasar — a contraction of the words quasi-stellar object — looks identical to a star when seen through a telescope.
We're talking A LOT of power. Quasars shine 10 to 100,000 times brighter than the entire Milky Way galaxy. Like lighthouse beacons piercing the darkness across the Great Lakes, quasars are visible from one corner of the universe to the other. The quasar 2M1310-1714, seen five times over thanks to the lensing foreground galaxies, lies some 10 billion light-years from Earth, while the galaxies are a mere 3 billion light-years away.
Astounding any way you look at it.
"Astro" Bob King is a freelance writer for the Duluth News Tribune. Read more of his work at duluthnewstribune.com/astrobob.