What’s the Bright Star Near Moon today?

Do you see a bright ’star’ near the moon around now? You’re really seeing a planet, Jupiter.
On September 20, Jupiter is closer to Earth than it has been since 1963. It’s closer than it will be again until the year 2022 at 368 million miles away. On September 21, Earth will pass between Jupiter and the sun. As you can guess, these events – Jupiter near the moon, Jupiter closest to Earth, Earth passing between Jupiter and the sun – are all related.
All of these events make the next few days a wonderful time to see Jupiter. How to see it? Remember, Jupiter is in the moon’s vicinity from about September 18 to about September 23. You can’t miss it!

Jupiter – biggest planet in our solar system, central to its own system of orbiting moons – is rising in the east just after sunset now. It looks like a star, but it’s much brighter than any star in our night sky. We on Earth are in a very good place to see Jupiter in September and October 2010 for two reasons.

First, Earth will fly between Jupiter and sun on September 21, 2010. We go between Jupiter and the sun every 13 months. Each year, when that happens, our two worlds are always relatively close together.

We go between Jupiter and the sun that often because Earth takes a year to complete one orbit around the sun, while Jupiter – with its bigger orbit and slower motion in orbit – needs 12 years to orbit the sun once. Nearly every year, our world’s faster motion in orbit places Jupiter opposite the sun in our sky. Astronomers call this event an opposition of Jupiter.
Every year around the time of opposition, people notice Jupiter. Around September 21, 2010 the planet will be rising in the east as the sun sets in the west. It will be highest in the sky at midnight, and it will set in the west when the sun comes back to the east at dawn. By October, 2010 Jupiter will be minutely fainter as Earth flies ahead in orbit. But it will be even more noticeable because it will already be in the east when night falls.

Second, Jupiter will be closer on September 20 than it has been since 1963 – closer than it will be again until 2022. That’s happening because Jupiter’s orbit – like Earth’s orbit – isn’t perfectly round. Jupiter’s closest point to the sun in its 12-year orbit will come about six months from now, in March, 2011.

So we will be passing between Jupiter and the sun (Jupiter’s opposition) on September 21, 2010. And Jupiter will be closest to the sun in March, 2011. That is why Jupiter comes closest to us – at a distance of 368 million miles – around the time of this opposition. The exact date of Jupiter at its closest is September 20, 2010 – the day before opposition. The giant planet will be closer that day than it has been since 1963, and it won’t come so close to Earth again until the year 2022.
So look for Jupiter in the night sky, and expect it to be big and bright!
Jupiter and 4 largest moons

If you have ordinary binoculars lying around the house, be sure to turn them in Jupiter’s direction. Jupiter is always a fun object to see through binoculars, and that will be especially true this year since the planet is closest. Through binoculars, you can see one, two or more of the planet’s four largest moons, known as the Galilean satellites. They will appear as tiny ’stars’ strung out in a line bisecting the planet. (Image: Nabarun Sadhya)

A telescope would reveal even more detail within Jupiter’s cloudtops. Dedicated observers, who track this detail over years and decades, know that the planet has recently lost its South Equatorial Belt. At the same time, the Great Red Spot has intensified in color.
By the way, the planet Uranus – shining barely within the limit of visibility to the unaided eye, and best seen in a dark sky – will be less than a degree from Jupiter on the night of opposition, September 21. When the moon is not nearby, shedding its glare on the scene, look through binoculars for Uranus near Jupiter. Both planets will be visible in the same field of view.
Uranus is in opposition on the same night as Jupiter, in the sort of coincidental space line-up that happens frequently. The two come to opposition only 5 hours apart. People love it when planets and moons line up in space. On the night of Jupiter’s opposition – September 21, 2010 – Jupiter and Uranus will make a tiny line-up, a line-up of two, in space.
Why is the moon near Jupiter on the same nights that Jupiter is closest to Earth – the same nights that Earth is passing between Jupiter and the sun? We said all of these events are related. In fact, the moon is full on the night of September 22-23. This is the northern hemisphere’s full Harvest Moon. A full moon is always opposite the sun. When it’s at opposition – in other words, when Earth goes between the sun and Jupiter – Jupiter is opposite the sun, too. So, as we stand on Earth in the next few days, we’ll be looking outward toward the same direction in space – opposite the sun’s direction – to see both the moon and Jupiter.

So look for Jupiter! On September 20, Jupiter will be closer to Earth than it has been since the year 1963. On September 21, Jupiter will be opposite the sun as seen from Earth, rising at sunset and dominating the sky all night, shining more brightly than any star. On and around all of these nights, Jupiter will be near the moon!

Article from: Earth Sky

One Response to “What’s the Bright Star Near Moon today?”

  1. Saurabh Says:

    Thanks Vijay for posting this article. Actually, yesterday only, I was observing one bright star which was clearly standing out near the moon. I can’t remember vividly, if I have seen any star with so much luminosity. Not sure, what was it and was thinking of sharing with you in Wed class. And here comes the wonderful explanation, Awesome !!

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