Grab this chance for a rare sight this week

[cheesehead]

This week, Mercury and Jupiter are visible near each other in the west just after sunset.

Note "just after sunset". Not "at night".

"The smallest and largest planets dance in the west tonight"

http://blogs.discovermagazine.com/ba...-west-tonight/

If you have good eyes and a flat horizon, then you can spot Jupiter and Mercury this week as they pass each other in the night twilight.

As the planets orbit the Sun, we see their position in the sky change. Right now, Jupiter is (apparently) getting closer to the Sun every day, setting in the west a bit earlier every night. Mercury, on the other hand, is apparently moving away from the Sun, getting higher off the horizon with each passing day. On the evenings of March 14 and 15th the two planets will pass each other, with a closest approach of roughly 2° — about 4 times the width of the full Moon. That’s actually pretty close, and they’ll make a pretty pair in the west just after sunset.

Here, in the article, there's an image created by software to illustrate the situation. Go to the article to see it.

(I've underlined a phrase in the following.)

And I do mean just. When the Sun sets, the two planets will be only about 10° off the horizon, where the sky will still be bright from twilight. Even though Jupiter will be shining at a magnitude of -2 (making it the fourth brightest natural object in the sky after the Sun, Moon, and Venus), and Mercury at -1, they might be a bit tough to see depending on your local conditions. Binoculars might help, but make sure the Sun is gone before scanning for the planets!

. . .

- - -

BTW, NASA's Messenger spacecraft will be entering orbit around Mercury on Thursday, the 17th. (Messenger will be the first spacecraft to ever do so.)

This timing is not entirely coincidental. NASA wanted the orbital insertion to occur near Mercury's elongation so that the angular separation from the Sun would make radio communication as reliable as possible.

"Messenger to enter [M]ercury orbit"

http://www.physorg.com/news/2011-03-...ury-orbit.html

So, if you get a good view of Mercury tonighttwilight or tomorrow, take your kids out again at sunset Thursday, if your sky is clear, so you and they can say they saw Mercury the same day the first spacecraft went into orbit around it.

[science_man_88]

Originally Posted by cheesehead

This week, Mercury and Jupiter are visible near each other in the west just after sunset.

Note "just after sunset". Not "at night".

"The smallest and largest planets dance in the west tonight"

http://blogs.discovermagazine.com/ba...-west-tonight/

Here, in the article, there's an image created by software to illustrate the situation. Go to the article to see it.

(I've underlined a phrase in the following.)
Coincidentally, NASA's Messenger spacecraft will be entering orbit around Mercury on Thursday, the 17th. (Messenger will be the first spacecraft to ever do so.)

"Messenger to enter [M]ercury orbit"

http://www.physorg.com/news/2011-03-...ury-orbit.html

I would but I bet it's too low for me to see. though a full moon is very large here.

[cheesehead]

Originally Posted by science_man_88

I would but I bet it's too low for me to see. though a full moon is very large here.

Is there somewhere nearby where there's a flat, low horizon to the west?

Mercury's distance above the horizon just after sunset will be about twenty times the full moon's diameter (the full moon would never be in the same direction as Mercury).

[science_man_88]

Originally Posted by cheesehead

Is there somewhere nearby where there's a flat, low horizon to the west?

Mercury's distance above the horizon just after sunset will be about twenty times the full moon's diameter (the full moon would never be in the same direction as Mercury).

well we'd have a near flat one but a few trees get in the way, 20 times the full moon by my estimate puts it in the east sky, the full moon here look like 2 inches big so that means about 40 inches it should be, visible or over the other side of my house from the sunset as for if I could see the whole thing I doubt it.

[ewmayer]

So it'll be around 40 inches above the horizon, then, eh? Yeah, I guess you'll really need an unobstructed view.

[Translation: Those too stupid to figure out where to look don't deserve to see.]

[cheesehead]

Originally Posted by science_man_88

well we'd have a near flat one but a few trees get in the way, 20 times the full moon by my estimate puts it in the east sky

No. it's in the west.

the full moon here look like 2 inches big

The full moon is 1/2 degree wide.

so that means about 40 inches

10 degrees.

Ten degrees is about the same angle as from one side of your fist to the other when held at arm's length.

Just after sunset, Mercury will be about one fist-width above the western horizon.

[cheesehead]

Not too big on education today, eh, Ernst?

[science_man_88]

Originally Posted by ewmayer

So it'll be around 40 inches above the horizon, then, eh? Yeah, I guess you'll really need an unobstructed view.

[Translation: Those too stupid to figure out where to look don't deserve to see.]

when I think west sky i think on the horizon I'm sorry, and 40 inches was an estimate.

[science_man_88]

my mom said that the sun and earth will be the closest they've ever been on the 19th or 20th, don't know where she heard that.

[ewmayer]

Originally Posted by cheesehead

Not too big on education today, eh, Ernst?

I'm always big big on education - for the educatable. [And we always presume the latter to be true, until proven otherwise, as amply demonstrated by our current 'tis better to remain silent and be thought a fool' award winner].

[Uncwilly]

Originally Posted by science_man_88

my mom said that the sun and earth will be the closest they've ever been on the 19th or 20th, don't know where she heard that.

More likely she heard that it was the earth and the moon. It is just closest in a while and at full.