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James: Welcome to Star Gazers. I'm James Albury,
Dean: And I'm Dean Regas, this week we'll talk about three bright
planets in your evening sky and the bright star we see most often.
James: Monday night March 12th look west after sunset and you'll
see two brilliant points of light that might be the eyes of some
fierce creature staring back at you, somewhat like Alice's famous
cat.
Dean: These two eyes in the night are really the two brightest
planets in our solar system, Jupiter and Venus. Venus, the one
on the right, is about 7 times brighter than Jupiter mainly because
it is so much closer to us.
James: Yes, Venus on Monday night will be 81 million miles away
while Jupiter will be 6 _ times farther, over 522 million miles.
Another way to think of it is that the light we see from Jupiter
takes almost 48 minutes to get here while the light from Venus
takes only about 7 minutes to get here.
Dean: Be sure to get out Monday night and take a look since seeing
Venus and Jupiter close together in a dark sky after sunset is
quite rare. If it's cloudy Monday night don't worry because the
next night Tuesday the 13th Venus will actually be a bit closer
to Jupiter but it will also be a bit higher. Venus has an 8-year
cycle of sky appearances. And this is the year that Venus gets
highest in the sky after sunset. And luckily for us Jupiter just
happens to be nearby. You won't have another chance to see Venus
and Jupiter put on a show nearly as good as this until March 1st
of 2023.
James: Venus will keep getting higher above the Sun each night
and Jupiter will drop lower each night for the rest of March.
But Jupiter and Venus aren't the only bright-planet game in town
next week. Turn and look east in the early evening and the bright
red-orange light of Mars will stare you in the face. Mars is as
big and bright as it will be for this year so this is prime Mars
watching time. Here are a few Mars images from Dr. Don Parker.
These are from January because that's when we record the show
but there will be many more and more recent Mars images from Dr.
Parker on our stargazersonline.org web site. Check them out.
Dean: Now let's ask you a star question. What is the bright star
we see in the night sky the most? Now you know that the sky is
always slowly changing and we don't always see the same stars.
So, the bright star we see most often from the northern hemisphere
is the bright star closest to the North Star. Let's show you:
James: O.K., we've got our skies set up facing north any evening
next week just after it gets dark and to find this star which
we see most often simply locate the Big Dipper right in front
of you, then shoot an imaginary arrow through the two stars that
mark the rim of the cup in the direction opposite the handle and
you'll land smack dab on the bright golden-yellow giant star Capella
which is the brightest star of the constellation Auriga the charioteer.
Dean: Now Capella is not the eye or shoulder of Auriga, or even
a star in his chariot. Strangely enough Capella means "the
goat star". You see Auriga was depicted not only as a charioteer
but also as a goat herder. In fact if you imagine that Capella
is a nanny goat you can see her 3 kid goats very close by.
James: Now although Capella looks like a single bright golden-yellow
star to both the naked eye and through a telescope, it's not.
You see years ago in 1899 an instrument called the spectroscope
revealed that Capella is 2 giant stars, each of them several times
larger than our Sun, but separated by only 70 million miles. That's
23 million miles closer than our Earth is to our Sun.
Dean: And things got even stranger a few years later when 2 more
stars were discovered to be part of the Capella system, 2 tiny
red dwarf stars a trillion miles away from Capella. So when we
look at golden-yellow Capella we are actually seeing 2 giant yellow
stars orbiting each other plus 2 red dwarf stars orbiting each
other.
James: So shoot an arrow through the rim stars of the big dipper's
cup and you'll land right on the strange and marvelous quadruple
star system, which we see as a single star, golden yellow Capella,
the goat star.
Both: keep looking up!
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James: This week we'll talk about three bright
planets in your evening sky.
Stop and drop
James: Monday night March 12th look west after sunset and you'll
see two brilliant points of light Jupiter and Venus. Venus, the
one on the right, is about 7 times brighter than Jupiter mainly
because it is so much closer to us.
Dean: Be sure to get out Monday night and take a look since seeing
Venus and Jupiter close together in a dark sky after sunset is
quite rare. If it's cloudy Monday night don't worry because the
next night Tuesday the 13th Venus will actually be a bit closer.
James: But Jupiter and Venus aren't the only bright-planet game
in town next week. Turn and look east in the early evening and
the bright red-orange light of Mars will stare you in the face.
Mars is as big and bright as it will get for this year so this
is prime Mars watching time.
Dean So, look for Venus and Jupiter in the west and Mars in the
east.
Both: Keep looking up
How did you like this episode?
Please give us your comments. (Click
Here)
* This week's Sky At A Glance and
Planet Roundup from Sky & Telescope.
This week's Sky At A Glance displays current week only.
Starry Night 6 was used to produce this episode
of "Star Gazers"