The Sun pauses in its apparent northern movement at the Summer Solstice (solstice = sun stop) at 1:04am EDT on June 21. After this, the days will get shorter, but for now the summer sun gives us short nights for observing, but the prime time evening skies are teeming with fun astronomical sights.
For the brief nighttime hours, Saturn is a three-ring circus all by itself. The pale planet and its rings and moons are up all evening, mid-way up in the southeast. Saturn is a little smaller in the telescope than when it was at opposition at the end of April, and it’s rings are a little bit less open this month, but not enough to spoil the fun of looking at Saturn.
The long twilights mean lots of satellites to spot overhead. After applying a little insect repellent, lie out for an hour and count the stately moving objects crossing our skies. The International Space Station is visible every 96 minutes during the night for the first half of June. After that, through June 24th, the best times to see the ISS are in the evening after sunset.
This is a great month to see Mercury! Just after sunset, look out to a clear northwestern sky – where the Sun just set. About 30 minutes or so after sunset, brilliant Venus is visible first. Then about 45 minutes after sunset, Mercury should appear in the twilight, starting the month a short distance above Venus. After the 7th, Mercury sinks to the left of Venus and dims substantially, but it’s nice to have magnitude -3.1 Venus to point the way to Mercury, even if they are low in the northwestern sky.
In a telescope, Mercury is half full around the 10th and whittles down to a crescent about the 18th. Venus looks just slightly out of round, and despite being almost three times larger than Mercury, it looks only a bit larger than Mercury, since Mercury continues to hold the title for ‘closest planet’ to Earth and Venus is on the other side of the Sun from Earth. Jupiter completes its dive into the solar glare a few days into June. Watch for Jupiter in the SOHO solar observatory’s LASCO C3 photos around the date of its solar conjunction on the 19th.
June’s full Moon is the closest of the year, with full Moon occurring only about a half-hour from the Moon’s closest approach to the Earth for the month. Watch out for higher than normal tides around the 23rd. Can you see the difference from normal high tide at your favorite beach? Moonrise on 22nd and 23rd will be especially photogenic – look for interesting foreground objects to compare to the rising Moon. On the 18th, the Moon sets up shop between Saturn and Spica – Saturn’s on the left and Spica on the right. The spiky crescent Moon joins Mercury and Venus on the 10th.
Mars is deep in the solar glare in the morning sky, but getting far enough out from behind the Sun so normal communications are resuming with the orbiting spacecraft and Opportunity and Curiosity rovers.
Take a look at Buzz Aldrin’s new book Mission to Mars, where he applies his MIT degree and experience in orbital mechanics to how humans can establish a beachhead on Mars. Do you doubt Buzz’s orbital mechanics abilities? Check out Buzz’s Gemini 12 flight when he used the back-up tables he had prepared for NASA to plot the rendezvous with the Agena docking target when Gemini’s rendezvous radar failed. Another research and discussion question students of the space program: Did Buzz’s insistence on practicing underwater for his EVAs save the U.S .space program?