Solstice Moon: June 20 at 6:34 p.m. ET (10:34 UT) marks the start of the summer season in the Northern Hemisphere and winter in the Southern Hemisphere. At this precise moment, Earth’s northern axis is most tilted toward the sun. On this date for sky-watchers, the sun reaches its farthest point north in Earth’s sky.
Coincidently, this year the moon reaches its full phase on the same date at 7:02 a.m. ET (11:02 UT). Having the full moon and June solstice on the same day has not happened in many decades. Check out our full viewer’s guide to seeing the solstice moon.
Mars Tempest: The red planet passed its best visibility only a month ago and still offers great views for backyard telescope users. Telescopes with at least a six-inch (15-centimeter) mirror can tease out a variety of subtle details, including dark markings and a white north polar cap. And amateur astronomers are even reporting possible signs of a small Martian dust storm.
NASA announced just last week that its Mars orbiters have been able to discern seasonal patterns in the planet’s dust storms. Observations of dust and temperature patterns from the past six Martian years show that three distinct types of regional dust storms happen in the same sequence at the same times every year.
This kind of information on potentially hazardous dust storms will be valuable for any future robotic and human missions.
For earthbound Mars watchers, our neighboring world will appear to ride high in the southern sky this week. The planet will shine with a ruddy color and will be much brighter than any of its surrounding stars in the constellation Libra, the balance.
Vega Rising: As darkness falls on June 22, look toward due east for a rising, very bright star.
This blue-white star is Vega, the lead member of the tiny constellation Lyra, the harp. Vega is one of the brightest stars visible all summer long throughout the entire Northern Hemisphere. Relatively nearby at 25 light-years, Vega shines so brightly because it is three times the size of our sun and produces 50 times as much light.
In 1983, astronomers discovered a disk of dusty material whirling around the relatively young star that looks similar to the Kuiper belt, the region of icy bodies beyond the orbit of Neptune in our solar system. That may indicate the early stages of evolution for a new planetary system.
Pluto Hunt: From late night on June 25 into the early morning hours of June 26, sky-watchers will have a great chance to track down the famous dwarf planet Pluto. The frozen little world will be passing very close to the faint naked-eye star Pi Sagittarii, to the left of Omicron Sagittarii, in the constellation Sagittarius, which will make for a convenient guidepost.
Be prepared to use a medium-size telescope with at least an eight-inch (20-centimeter) mirror and to be under dark sky conditions—Pluto glows at a feeble magnitude 14.1. To put that into perspective, higher apparent magnitude numbers mean fainter objects. Even under the darkest skies, the human eye can see only up to magnitude 6, while binoculars usually get you to magnitude 8 to 10.