Saturday's full moon offers strange illusion

[Owlscrying]

June 29

This weekend's full moon hangs lower in the sky than any other full moon of 2007, according to NASA, and it's a good time to be fooled.

When low on the horizon, the Moon can appear to be larger than when it's higher in the sky. It's all an illusion, scientists say, and it does not involve any enlarging effects of the atmosphere.

Our brains think things on the horizon are farther away than stuff overhead, because we're used to seeing overhead clouds that are close compared to those on the horizon. In the mind's eye, the sky is a flattened dome.

With this dome as a reference, we expect something on the horizon (such as the moon) to be father, and because it is actually no farther than when overhead, our brains goof and imagine that it is larger.

Officially, the moon will be full Saturday June 30 at 9:49 a.m. ET. Of course, you'll want to do your looking in the evening.

The big-moon-rising effect will be evident Friday, Saturday and Sunday. On each evening, the moon will appear nearly full.

While you're out, check out Venus and Saturn, which are close together in the western sky as darkness falls.

So why is one full moon lower in the sky than another? The moon's orbit around Earth is tilted 5 degrees compared to the plane of Earth's travels around the Sun, and Earth itself is tilted on its rotational axis. All this accounts for the lunar phases, and it also means the moon's path through our sky can be higher or lower depending on the angles on any given night.

The complex orbit of the Earth-moon system is constantly evolving, too. Right now, the moon is moving away from us by more than 1.5 inches every year.

go

[Picturesque Orion]

Well, thats great news. I am looking foward to this.

[louie]

Id like to see that, but were having baiscally 24 hours of brightness at the moment, so i probably wont get to see it.

[bluelight]

ugh... rainy I can't see it

[Princess Serenity]

June 29

This weekend's full moon hangs lower in the sky than any other full moon of 2007, according to NASA, and it's a good time to be fooled.

When low on the horizon, the Moon can appear to be larger than when it's higher in the sky. It's all an illusion, scientists say, and it does not involve any enlarging effects of the atmosphere.

Our brains think things on the horizon are farther away than stuff overhead, because we're used to seeing overhead clouds that are close compared to those on the horizon. In the mind's eye, the sky is a flattened dome.

With this dome as a reference, we expect something on the horizon (such as the moon) to be father, and because it is actually no farther than when overhead, our brains goof and imagine that it is larger.

Officially, the moon will be full Saturday June 30 at 9:49 a.m. ET. Of course, you'll want to do your looking in the evening.

The big-moon-rising effect will be evident Friday, Saturday and Sunday. On each evening, the moon will appear nearly full.

While you're out, check out Venus and Saturn, which are close together in the western sky as darkness falls.

So why is one full moon lower in the sky than another? The moon's orbit around Earth is tilted 5 degrees compared to the plane of Earth's travels around the Sun, and Earth itself is tilted on its rotational axis. All this accounts for the lunar phases, and it also means the moon's path through our sky can be higher or lower depending on the angles on any given night.

The complex orbit of the Earth-moon system is constantly evolving, too. Right now, the moon is moving away from us by more than 1.5 inches every year.

go

Oh cool. Thank you, Owlscrying. Hopefully, I'll be able to see it. ^^