This Week’s Sky at a Glance, 2025 May 31 – June 7
This Week’s Sky at a Glance, 2025 May 31 – June 7
Asteroids, like comets, are solar system objects that some amateur astronomers like to collect; that is, identify them at least once with binoculars or a telescope. They are not as interesting to see as comets are, being just points of light, but they are often more challenging to identify. If you are lucky one might be near an easily identifiable star or group of stars, and if you are even luckier you might be able to detect its movement relative to a star over an evening.
The first asteroid was discovered on January 1, 1801, and Ceres was initially called a planet once its orbit was calculated. In the 18th century a mathematical progression known as the Titius-Bode Law was formulated which fit the distances of the six known planets from the Sun. Uranus was discovered in 1781 and its distance fit that formula, but there was an inexplicable gap between Mars and Jupiter. Ceres filled that gap nicely, but over that decade three more new “planets” were found within the gap.
Ceres is by far the largest asteroid and it is now categorized as a dwarf planet along with distant Pluto, Eris, Makemake and Haumea. The Heavens-Above website has an Asteroids section which includes two maps for each of the brighter asteroids; one with a wide-field view of the constellations in the area, and an expanded inset with a binocular-size view showing the asteroid among the nearby stars. The brightest asteroid, Vesta, is currently in the evening sky in Virgo.
This Week in the Solar System
Saturday’s sunrise is at 5:40 and sunset will occur at 9:04, giving 15 hours, 24 minutes of daylight. Next Saturday the Sun will rise at 5:37 and set at 9:09, giving 15 hours, 32 minutes of daylight.
The Moon is near Mars this Saturday, Regulus on Sunday, at first quarter on Monday and approaching Spica on Thursday. Keep an eye on Mars as it races toward Regulus for a close conjunction in mid-June. Jupiter is sinking sunward, and on June 7 it meets up with Mercury heading in the opposite direction. Venus is at greatest elongation from the Sun on Sunday. Saturn rises before 3 am this weekend, with Neptune half a binocular field to the left.
The Spring Star Party at Kouchibouguac National Park takes place May 30-31. See the rascnb website for details. Tune in to the Sunday Night Astronomy Show at 8 pm on the YouTube channel and Facebook page of Astronomy by the Bay. The Saint John Astronomy Club meets in the Rockwood Park Interpretation Centre on June 7 at 7 pm.