From The Bishop’s Museum “Skywatch” webpage.
ETA AQUARIDS AND SMALLEST FULL MOON
We spent last month being “grounded” by the myriad of science events in town and I didn’t spend much time on things going on above our atmosphere. In contrast, this month is a bit busier with interesting sky-watching events as well as a number of human-generated activities in our solar system.
Starting with the natural events in our sky, May has the second of the two “really good” meteor showers of the year, with the best-coinciding Moon phase to look for meteors. The Moon is “new”, or dark during the shower, which means there is no moonlight to compete with the streaking lights, however staying away from city lights will make for even better seeing conditions. The Eta Aquarids will peak at 8:00 A.M. on May 5. The radiant of the shower rises in the constellation Aquarius almost directly due east by 2:30 A.M. on May 5, so between then and sunrise is the most ideal viewing time. The Eta Aquarids are leftover bits of Comet Halley making contact with our atmosphere. Often characterized as “dirty snowballs”, comets are essentially loosely packed material that “shed” as they travel through space, especially as they get warmed by the sun. This debris is often pieces no larger than pebbles or dust. Please note that because Aquarius will not rise until the early morning hours, it will not be included on this map. But don’t worry, you do not need a star map nor knowledge of the constellation to look for the Eta Aquarids if you go by the times and direction to look (east).
Speaking of the Moon, this month’s full Moon is the smallest of 2008. Remember that the Moon’s orbit is not perfectly circular but elliptical so there is a closest and farthest point to the Earth every month, called perigee and apogee, respectively. This month’s full Moon coincides with its apogee, therefore making it appear smaller in the sky. The difference visually is less than 10% and most people will probably not notice it, but pictures of the Moon compared at both extremes (perigee and apogee) will definitely show the difference. A good website for this is Astronomy Picture of the Day and search for “apogee” or “perigee”.
There are a lot of exciting missions heading off into space this month—starting closest to the Earth, the space shuttle Discovery is scheduled to launch the last day of May to the International Space Station (ISS). The shuttle carries more components for the Japanese laboratory KIBO and an astronaut from the Japan Aerospace Exploration Agency (JAXA) as a mission specialist. KIBO, which means “hope” in Japanese, will join the recently-added European Space Agency’s Columbus Lab and the existing research modules from the United States and Russia.
Moving further out into the solar system, NASA is anxiously waiting for May 25, when the newest Mars explorer touches down on the Red Planet. The Phoenix Mars Lander has been cruising the 422 million miles to the planet since it launched last August and will join the two Mars rovers, Spirit and Opportunity on the surface in the search for water and signs of habitability. While the rovers explore the equatorial region of Mars, Phoenix will be located at the north polar area. In comparison, if Phoenix were on Earth it would be in Northern Canada within the Arctic Circle. Water is the main ingredient for supporting life as we know it, and scientists are concentrating on this part of Mars because there is evidence of large amounts of water locked in the ice caps at the poles.
Phoenix is named after the mythical bird that bursts into flames as it dies, bringing forth a new bird from its ashes. The Phoenix Mars Lander carries instruments and spacecraft design from two unsuccessful missions, the Mars Polar Lander and the Mars Surveyor 2001 Lander, reviving the technology and making this mission the first to explore the icy polar region of the planet from the surface.
Lastly, a mission that will explore the farthest ends of the universe is also scheduled to launch in mid-May. NASA’s Gamma-Ray Large Area Space Telescope (GLAST) will search deep space for gamma-ray bursts, one of the most elusive and the most powerful forms of radiation in the universe. It is not known what causes these massive explosions of energy and scientists are hoping to determine whether exotic objects such as black holes or neutron stars are involved. GLAST will also study other sources of high-energy, like supernovas and pulsars, to help give more insight to our understanding of the universe.
Lahaina Noon season begins. Between May and July the sun passes directly overhead for areas within the Tropics. During Lahaina Noon objects that are directly perpendicular to the sun, such as flagpoles or fences, have no shadows since the “shadow” would be cast right “under” the object. Times vary by location, so check the website for more information: www.bishopmuseum.org/planetarium
Mercury is back in the western sky at sunset, low in the horizon during the first week of May and getting to its full height at mid-month. Although small, Mercury is fairly bright but is typically visible mostly during twilight because by the time the sky is fully dark the little planet is too low to the horizon for most people to see. (Unless you have a clear view to the west)
Unfortunately the brightest planet is no match for the brightest star in our sky. Venus is very close to the sun right now and will move behind it next month. The casual observer will have a difficult time spotting it the few minutes before the sun rises in the first week of the month.
Mars moves from Gemini into Cancer during this month and towards the end of the month (May 21-23) and passes through a nice binocular cluster, M44 or the Beehive Cluster. During the first couple of weeks while the planet is still in Gemini, however, look for the fading planet next to the two brothers’ “heads” at the east of the constellation. It is still as bright as Pollux (the more eastern twin) but continues to fade as it recedes from Earth. On May 9 a crescent Moon joins the group as Mars makes its way eastward. The constellation Cancer contains few bright stars discernable from the city, so it is not included on the map, but follow Mars’ path through the month and see if you can spot the cluster of hundreds of stars with binoculars during its trek through the Beehive!
Jupiter rises right around midnight the first few days of the month and almost half an hour earlier by just the first week. By the end of the month the giant planet will rise by 10:00 P.M. Jupiter is to the east of the “teapot handle” of Sagittarius, but you won’t have any trouble finding it in the sky because of its brightness.
At the start of May Saturn is almost at zenith at nightfall and next to the “heart” of the constellation Leo. If you are looking at Mars during the month with binoculars, don’t pass up the chance to spot Saturn while you’re at it since they are in the same part of the sky.
To see video of exploring the lava flow, go here and here; for more information on exploring the Big Island, go here and here; for information on renting GPS-guided tours of the Big Island, go here to see a video demonstration of GPS-guided tours of the Big Island, go here.