¡SkyCaramba! Weekly astronomy blog for the week ending July 7, 2012
You probably haven’t seen Jupiter and Venus in a while. They’ve spent several weeks too close to the sun for us to see, although Venus did get right in between the earth and sun for people in just the right places to see its silhouette last month. Both planets are reemerging in the morning sky this month.
If you can recognize the Pleiades in the east a little before sunrise, look below them. You should see two or three bright dots. The one closest to the Pleiades is Jupiter. Below it is Venus. And a little below it, you may be able to see the orange star Aldebaran. Aldebaran makes part of a V shaped asterism called the Hyades. Venus is right in the middle of the Hyades as July starts.
The complete V of the Hyades may be a little hard to see as sunrise approaches. For people in the northern hemisphere, it gets easier to see day by day as the sun moves a little further from the asterism and rises later each morning.
Jupiter is almost 540 million miles or 860 million kilometers away from us at this time. Venus is about 36 million miles or 58 million kilometers away. Aldebaran’s light is reaching us after a 65 year journey.
One week into July, Jupiter will have moved a little lower and to the left compared to where it started on the starry backdrop. Venus will have moved too. It’s closest to Aldebaran on the 9th at 0.9° away.
Keep watching this month as Venus keeps moving to the left and Jupiter comes near Ain, the star on top of the side of the V opposite Aldebaran. On the 23rd and 24th, Jupiter and Ain will be 1.8° apart. By then, northern hemisphere sky watchers will have an easy view of the Hyades. Venus will be moving on clearly heading for its next destination.
Venus will be at aphelion on the 11th. That’s when it’s the farthest from the sun in its orbit. That’s just a few days after Earth is at aphelion and a day before Mercury reaches aphelion. Jupiter won’t be at aphelion until 2017. It was at perihelion, its closest to the sun, last year.
In Greek mythology, the Hyades are young women weeping because their brother Hyas was killed in a hunting accident. They were put in the sky where their tears provide spring and summer showers.
By the end of July, you shouldn’t have trouble spotting Betelgeuse, another orange star, rising a little before the sun. The star is in one shoulder of Orion. Northerners think of Orion as a winter constellation because that’s when it’s up all night, but there it is wishing us good morning at the start of a hot summer day.
¡SkyCaramba!