This is the Dudley Observatory Skywatch Line for Wednesday, March 11th, and Thursday, March 12th, written by Louis Suarato.
The 93% illuminated, waning gibbous Moon rises at 9:28p.m. Wednesday in the constellation Virgo. Virgo’s brightest star, Spica, shines 7 degrees to the Moon’s right. After sunset, look for the brightest planet, Venus, shining at magnitude -4.37, about 34 degrees over the west-southwestern horizon, and the brightest star, Sirius, shining at magnitude -1.45, about 30 degrees above the south-southeastern horizon. Mars leads the procession of outer planets when it rises at 4:16 a.m. Thursday. Jupiter rises 13 minutes later, followed by Saturn 26 minutes after Jupiter rises. The 3 planets span 13 degrees within the constellation Sagittarius.
Thursday morning, while the 3 planets are visible, there will be a very bright International Space Station pass over our region. The ISS, shining at magnitude -3.80, will emerge at 5:48 a.m. out of the northwest in mid-sky between the Big Dipper and Leo. The ISS will then head toward Bootes, passing its brightest star, Arcturus. The space station continues its southeasterly trek through Ophiuchus before it heads toward Sagittarius when it will fly very close to Jupiter, between Mars and Saturn.
Ophiuchus has been in the news lately as astronomers have reported the largest ever cosmic explosion which emanated from that constellation. The blast through a galaxy cluster, the equivalent of one billion supernova explosions, released five times more energy than the previous record for such a blast, and blew a crater more than a million light-years wide through the galaxy cluster. Simona Giacintucci, a radio astronomer of the Naval Research Laboratory in Washington D.C. stated “A key difference is that you could fit 5 Milky Way galaxies in a row into the crater this eruption punched into the cluster’s hot gas.” The Ophiuchus galaxy cluster is located 390 million light-years away. Giacintucci and her colleagues believe the source was a super-massive black hole within one of the galaxies.