Wednesday, June 02 2010 @ 02:37 pm CDT
Contributed by: dgrosvold
Starting on Thursday evening, Mars is within 3° of Regulus in the constellation Leo. They're almost the same brightness, and make a striking color-contrast pair high in the west after dark. Follow them each evening until they reach conjunction on Sunday, June 6th, when they will be only 0.8° apart.
The bright Evening Star shining in the west-northwest during and after twilight is Venus. The twins of Gemini, Pollux and Castor, are above it. Venus is about as high in twilight as it will get this year in this part of the world. Venus is still a small gibbous disk in a telescope. It's so dazzlingly bright that you'll have the best telescopic views of it in the bright blue sky before sunset when the contrast is lower. After sunset, you may want to use a polarizing or neutral density filter to cut the glare. Later in the summer, Venus will be closer to Earth, and easier to view when larger and in its crescent phase.
Also this week, the faint comet C/2009 R1 (McNaught) is nearing its period of best visibility in mid-June at magnitude 7.8. Look for it low in the northeast just before the start of dawn with binoculars or a small telescope.
Saturn glows high in the southwest during the evening this week. In a telescope, Saturn's rings are tilted a mere 1.7° from edge-on, their minimum tilt for the next 15 years. Look for the thin black shadow-line cast by the rings across Saturn's bright globe.
The ISS (International Space Station) will make several overhead passes during the early morning hours this week. The brightest of these will occur on Sunday and Tuesday mornings, both near magnitude -3.5. On Sunday morning, look for the ISS to rise in the SW at 5:31 AM, and pass overhead at a maximum altitude of 83° at 5:33 AM in the SE before setting in the NE at 5:36 AM. A bit earlier on Tuesday morning, the ISS will rise at 4:44 AM in the SW, reach a maximum altitude of 82° in the SE at 4:45 AM, and then set in the NE at 4:48 AM. The ISS will also make passes on Saturday and Monday mornings but will only reach a maximum brightness of magnitude -1.3 on these passes.
There will also be several bright Iridium Flares this week in the early morning hours, with several reaching fairly bright magnitudes. But if you’re out and about in the evening on Thursday, June 3rd, try to catch Iridium 18 at an altitude of 63° in the eastern sky at 9:06 PM.
Check the Heavens Above website for times and positions of Iridium Flares, the ISS, and other satellites in the nighttime sky. You can also view a current finder chart for comet C/2009 R1 (McNaught) on the Heavens Above website.