Planet Inventory
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It’s time we did another planet safari! In the months since we last went hunting, our big friends have been migrating about all over the sky. Let’s find out where they can be found for the next month or two. We’ll begin in the early evening and work our way through the night.
Jupiter and Saturn, the two bright planets that have ruled the night skies all through the winter months are now going down with the setting sun. Their glory time is fading fast.
Remember that Earth, being closer to the sun than Jupiter
and Saturn, speeds around the sun much faster than they. In fact, we have
pulled ahead so far that we are now on the whole other side of the solar
system than the two gas giants. Soon they will be on the far side of the
sun, vanishing into its brightness.
You can follow this yourself in the coming weeks. Jupiter is the bright
star-like orb about 45 degrees high in the western skies after the sun
sets. Saturn is dimmer and just below Jupiter, leading it into the horizon.
Watch the two during April and May as they appear to creep closer to our
sun, actually moving behind it.
And you may want to mark April 24 and 25 on the calendar. The crescent
Moon moves through them both during this time, providing a gloriously
beautiful early evening sky.
We are also on the inside track compared to another outer
neighbor, our near and dear friend, Mars. However, in the case of the
Red Planet, we are currently catching up with it.
Thinking cap time! Since we are catching up with it on our inside lane,
Mars, unlike Jupiter and Saturn, will soon be on the whole opposite side
of the earth as the sun is. Meaning, we can see Mars in our late night
skies when the sun is shining brightly on the daylight side of our planet.
As we pass Mars in the next couple of months, it will rise earlier and
earlier in the evening and because we are getting closer it will get plenty
bigger, as well. That’s good news for those of us with telescopes.
A good scope will be able to pick out surface features, including the
polar ice caps.
The Solar System on 1 April. See
a movie of this from April to June (873K)
So what’s happened to Venus? For months it has been
riding high in the western skies during the evening. Now it’s gone.
Where’d it go?
Venus, unlike our outer friends, is closer to the sun than we are, so,
compared to us, it is on an inside track and travels around in its orbit
faster than we do. Bottom line: It has passed us recently, swinging between
the sun and us, and is now leading us on the “morning” side
of the sun.
At the beginning of April Venus appears very near the sun, but as the
month goes by and passes into May, it will speed way out in front of us
on its inside lane and appear higher and higher in the morning sky.
Those of us who drive to work early in the morning toward the east - just
before sunrise - will notice the Morning Star pull away from the sun as
days go by.
Getting a mental image of all this is not so easy. Use the images below
(and above) for movies of what we've discussed.
Mark Ritter has been spotted teaching astronomy in Temecula and can be reached at ritter@firstlightastro.com.
Jupiter and
Saturn setting closer to sun (7.30 PM from April to July; each frame
is one week) (134K)
Venus rising
before sunrise (about 5.30 AM from April to July; each frame is one
week) (173K)
Posted by Administrator at 2001.04. 1 08:40 AM | Comments (0)
