Avid skywatchers had a chance to witness tonight’s close pairing between Jupiter and the First Quarter Moon — a nice sky event that kicked off the celebration of the National Astronomy Week 2013 in the Philippines. If you look closely at Jupiter in this image, you’ll also see a hint of its 4 Galilean moons.
During the closest approach, Jupiter and the Moon were 0.5 degree apart. For comparison, the angle covered by the diameter of the full moon is about 31 arcmin or 0.5 degree.
Astronomers use angular measurements to describe the apparent size of an object, or the distance between them. Knowing how to measure angular distance is an essential skill to finding your way around the sky.
On my way home after attending tonight’s Christmas Day Mass, I saw a faint ring or halo around the Moon. Lunar halos often result when moonlight enters randomly- oriented hexagonal ice crystals in wispy cirrus clouds. Refraction of light produces a 22 degree ring or halo around the Moon. In order for a halo to appear, the Moon must be at least 22 degrees above the horizon. Interestingly, Jupiter was also positioned inside the 22 degree halo on this night near the waxing gibbous moon.
Lunar halos usually indicate that a bad weather is on it’s way. In the Philippines, a new tropical depression is expected to bring heavy rains across central part of the country in the next few days.
Image taken using hand-held Canon Powershot SX40 HS.
Merry Christmas, folks!
During the early morning hours of August 12, Philippine sky observers had a great chance of witnessing a relatively rare occultation of Jupiter (and some of its largest satellites) by our Moon. In astronomy, an occultation is an event that occurs when an apparently larger body passes in front of an apparently smaller one. In this case, the moon passed in front of the planet Jupiter; the pair being visible in the morning sky in the Philippines about 5 hours and 53 minutes before the Sun. At the moment of closest approach, the Moon was at mag -11.3, and Jupiter at mag -2.2, both in the constellation Taurus.
Despite the presence of hazy skies and thin clouds, we were lucky to have been able to observed the occultation event. Once I located the moon with my naked eye, I immediately pointed my superzoom camera to it and took an image. I found Jupiter close to the moon but it was covered with haze. A few minutes later, Jupiter slipped behind the bright lunar limb and was visible no longer. Half an hour later, I tried to capture a video of the reappearance of Jupiter, but the clouds had thickened to the point where I could no longer find the moon. When the clouds had finally gone out of sight, Jupiter was already emerging from behind the dark limb.
Still, considering the less-than-ideal conditions, it was quite a successful observation. 🙂
Sky condition: 70-80% cloudy
Camera used: Canon Powershot SX40 HS
I observed this event from Marikina City.