Astronomy Picture of the Day 6-21-02

NASA ^ | 6-21-02 | Robert Nemiroff and Jerry Bonnell

[petuniasevan]

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2002 June 21

Zimbabwe Sunset
Credit & Copyright: Murray Alexander

Explanation: Today's scheduled geocentric astronomical event is the Solstice, with the Sun reaching its northernmost declination at 13 hours 24 minutes Universal Time. For denizens of planet Earth this Solstice marks the begining of Summer in the northern hemisphere and Winter in the south. Of course, the tilt of the Earth's axis of rotation (and not a change in the Earth-Sun distance) is mainly responsible for the changing seasons and the Sun's yearly north-south motion through the sky. Following the rising and setting points of the Sun along the horizon is one way to track the Sun's progress along its seasonal cycle. Tall grasses and tinted clouds frame this dramatic view of the setting Sun approaching the northern limit of this year's seasonal journey as seen near Raffingora, Zimbabwe.

[petuniasevan]

Summer's here! (Or winter, for those of you "down under"!)
The earth is actually 2 1/2 million miles farther from the sun now than it will be in January.
The seasons are a result of the earth's axial tilt of 23 1/2 degrees.
If you live north of 55 degrees north latitude, summer nights will stay light.
North of the Arctic circle, the sun won't even set for weeks to come.
At 45 degrees north latitude, I'm experiencing maybe 5 hours of total darkness. Sunrise at 5:10 AM; sunset at 8:40 PM.
On the other hand, if you're in Miami FL, your sunrise is 6:30 AM and sunset 8:15 PM.

Get on the APOD PING list!

[petuniasevan]

APOD PING!

[RightWhale]

At 64 north we are experiencing no nights of total darkness and haven't for a couple of months, nor will we for a couple more months. The sun sets, but not far, and the twilight isn't deep.

[altair]

The sun is setting on Zimbabwe. Hmmm. I wonder if that has some significance given the current political climate there.

the tilt of the Earth's axis of rotation (and not a change in the Earth-Sun distance) is mainly responsible for the changing seasons

As a point of trivia, in the northern hemisphere, the earth reaches perigee (closest to the Sun) in the winter and apogee in the summer.

[MeekOneGOP]

Beautiful. Thanks!

[boris]

Pretty, but this is not an astronomy photograph.

I am increasingly unhappy (big deal, I know) with "beauty" scenery shots masquerading as astrophotos--such as "the Moon and Venus over Geneva" a few days ago.

Can we agree that an "astronomy" photo ought to involve--in some way--a telescope? Is that too much to ask?

--Boris

[RightWhale]

Sure, it isn't astronomy as we know it. Sometimes we overlook the fact that earth is also in the universe. Kepler, Terrestrial Planet Finder, Darwin, and Eddington are upcoming missions to space intended to find planets and perhaps life out there. Within a few years there will be images of other planets out side the solar system. --[mental shift]-- The stars will become suns. Who knows, perhaps an image of sunset over a distant planet will be as commonplace one day as what we have been looking at right here forever. And when we are on Mars looking back at earth, that will be astronomy for sure.

[Mike Darancette]

Too bad that such a beautiful country is afflicted with such a horrendous government.

[petuniasevan]

The problem is this.
I'm reposting the APOD from NASA's site.
I post what they post.
If you have an objection, follow the link and email Robert Nemiroff or Jerry Bonnell.
It's their choice of photos.

I've seen plenty of astronomical photos not taken through a telescope...

Maybe your definition of astronomy is too rigid.