A truly eye-catching pairing of our moon and a neighboring diamond-like world sparkles in the sky this week, while the Milky Way and shooting stars hit prime time.
Moon and Venus. Early morning risers in the Americas on Tuesday, June 24, will get a chance to see the crescent moon pair up with brilliant Venus. The spectacular pairing (which should make for a great photo opportunity) will be visible low in the eastern sky about 45 minutes before local sunrise. With the two objects separated by no more than one degree, equal to two side-by-side full moon disks, this is a celestial event you won’t want to miss. (See related: “Will Venus Express Spacecraft Crash or Keep Decoding Planet’s Secrets?“)
While you’re soaking in the beauty of this cosmic duo, it would be a great time to check out the “Earthshine” phenomenon, which illuminates the unlit part of the moon’s round disk. Sunlight reflects off the Earth’s oceans and clouds, lighting up the dark portion of the moon for sky-watchers.
Moon and Aldebaran. On Wednesday, June 25, look for the moon to pay a visit to Aldebaran, the red eye of Taurus, the bull. The challenging duo will be extremely low on the eastern horizon, with the best visibility coming at about 20 to 30 minutes before sunrise.
You will need to find an elevated location, one that has a totally clear view of the eastern horizon without any obstructions, to catch this subtle event.
If the brightening dawn light is hiding the pair, try searching with binoculars.
Mercury challenge. The next stop for the moon is elusive Mercury. On Thursday, June 26, just before sunrise, the razor-thin waning crescent moon will act as a guide to the innermost planet. Both objects will be hugging the eastern horizon, making it extremely challenging to observe with just the naked eye. That means binoculars will be your best bet. Sky-watchers in the southern United States and more southern latitudes will be best positioned to hunt for this event. (See related: “Mercury “Hollows” Found—Pits May Be Solar System First.”)
Bootid meteors. In the predawn hours of Friday, June 27, sky-watchers get a chance to get a good glimpse of the annual Bootid meteor shower, thanks to a dark, moonless sky. While outbursts of 50 to 100 meteors per hour occurred in 1998 and 2004, this year appears to be more of an average year for the Bootids, with a much more modest dozen or so shooting stars per hour at peak hours. As with most other showers, the Bootids are thought to be caused by sand-grain-size debris left over from a passing comet. The culprit comet in this case is Pons-Winnecke, which circles the sun every 6.4 years.
The meteors will appear to radiate from the low northwestern sky within the constellation Bootes the Herdsman, hence their name.
In general, Bootids are known to be bright and relatively slow meteors with speeds around 40,000 miles (64,000 kilometers) an hour—less than a third the speed of most other annual meteors.
Milky Way rising. With the moon currently in its new phase and out of our skies, now is the best time to glimpse our own home galaxy. Late night on Saturday, June 28, look for the misty, white powder trail that is our Milky Way galaxy, stretching up from the northeastern horizon, arching high up the eastern sky, and then down to the southern horizon.
Best seen under dark skies, at least a half hour outside of brightly lit cities, the Milky Way that we see in the summertime represents a neighboring spiral arm of stars stretched out overhead and its dense, brighter core near the southern horizon, as seen from northern latitudes. (See related: “Scientists Unravel Secrets of Monster Black Hole at Center of Milky Way.”)
Scanning this whole region of the sky with binoculars will reveal that hazy glow to be a river of millions of glittering stars, all of them thousands of light-years distant.