Astronomy: The Week Ahead – Sun 28 Jun to Sat 4 Jul


Sunday June 28

Tonight’s waxing gibbous Moon is 11.8 days old and 90% illuminated. It is paired in tonight’s sky with Saturn, just over 2 degrees to its west. Both reside tonight in the constellation Libra. Below is Scorpius, with its brightest star Antares. Antares shines at magnitude 1.03, Saturn at 0.23, and the moon a brilliant magnitude -12.6!


Monday June 29

If you’re quick this morning, you’ll have another view of the planet Mercury, near Aldebaran in the constellation Taurus, just north of the eastern horizon.

There’s another interesting item in the sky to view though. The famous variable star Algol in Perseus is at its brightest, magnitude 2.0. Look at it this morning, then watch it over the next few dawns as it fades to 3rd magnitude, equal in brightness to the dimmer star to its right in this image.


Tuesday June 30

A spectacular conjunction occurs tonight, with the sky’s two brightest planets, Venus and Jupiter. They are so close together, the image here can’t show them as separate objects. You’ll be able to split them apart easily though, as they are 20 arcminutes apart. The diameter of the Moon is 30 arcminutes.

Look due west, an hour after sunset to see the pair, just below the sickle of Leo.


Wednesday July 1

If you have a clear western and eastern horizon you can watch Full Moon rising as the sun is setting. Try to do it! The Moon will be full in the constellation Sagittarius, above the asterism called the Teaspoon.

This is the summer’s first Full Moon, and was called the Full Buck Moon by Native Americans, as the bucks begin growing their antlers this month. Some called it the Thunder Moon, due to the frequency of thunderstorms in July.

July will have another full moon, so you’ll be able to see a Blue Moon this month too!


Thursday July 2

Morning skies in the east and southeast are beginning to show some of the water constellations. Cetus the whale. Pisces the fish. Aquarius the water carrier.


Friday July 3

The show continues in the west tonight, as Venus has moved clearly past Jupiter and the planets head toward a rendezvous with Regulus in Leo on the 14th. Have you even tried identifying some of the lesser known constellations around the famous Leo the Lion? Coma Berenices is behind its haunches. Leo Minor just over the mane of the big cat. Above them both, following the Great Bear (Ursa Major) and under the Big Dipper are the hunting dogs, Canes Venatici.


Saturday July 4

Here’s a celestial firework for the 4th of July. M13 is arguably the best globular cluster in the northern sky. It appears in a moderate size telescope much like a burst of star, or a firework. At magnitude 5.8, it is on edge of naked-eye visibility from a dark sky. It is large in apparent size, at 23 arcminutes (remember, the full moon is 30 arcminutes) and resides a full 25,100 light years away from earth, within our Milky Way galaxy, and is about 145 light years in diameter. Hard to imagine, this is a gravitational ball of several hundred thousand stars that are among the oldest (as globular clusters are) in the universe!

Happy viewing!