Student Features

Extreme Planets!
07.08.04
Imagine being able to dunk a basketball like a pro no matter how tall you are.

Picture a planet where high noon looks more like midnight on a moonlit night. Our Sun would be only a tiny, bright star.

Imagine living in a place where temperatures drop 600°C (1,080°F) at night.

Welcome to our solar system.

There are worlds out there cold enough to instantly freeze an explorer into a human popsicle. And others hot enough to boil a person into a wisp of steam in seconds flat. There's also poisonous air, steel-crushing atmospheric pressure and winds that make Earth's most intense tornados seem tame.

Read on to find out more amazing facts about our extreme solar system:

Image the boiling lave-like surface of the Sun with bright, wispy loops of gas flowing around dark sunspots
What a Blast
You'd need to explode 100,000,000,000 (one hundred billion) tons of dynamite every second to match the energy produced by the Sun.

Image to right: Even a relatively quiet day on the Sun is busy. This ultraviolet image shows bright, glowing arcs of gas flowing around the sunspots. Credit: NASA

Running Hot and Cold
Mercury is not only one of the hottest places in our solar system -- it's also among the coldest. As darkness falls on Mercury, temperatures can drop more than 600°C (1,080°F).

Backspin
If an action hero wanted to ride off into the sunset on Venus, she'd have to head east instead of west. Venus rotates in the opposite direction of the other planets -- a retrograde rotation -- so the Sun rises in the west and sets in the east.

Constant Bombardment
Earth is hit by up to 10,000,000 kilograms (22,000,000 pounds) of meteors each day -- and hardly anyone notices. Most of the material is dust-like grains so light they actually drift gently to Earth.

A Steady Hand
The Moon is more than a pretty accessory in our night sky. It stabilizes Earth's wobble, which led to a more stable climate and probably helped life evolve. The Moon also guides the ebb and flow of Earth's oceans.

Slam Dunk
With gravity only one-third of Earth's, there's a good chance just about anyone could dunk a basketball in an NBA-regulation goal on Mars. Unfortunately, the required spacesuit might cut down on your edge.

Color image of mile-wide hole in the Arizon desert created by an asteroid impact millions of years ago
Asteroid Assault
Asteroids have hit every planet in our solar system. Most space rocks that hit Earth burn up or slow down enough not to cause serious damage. Evidence of what happens when they don't can be seen at Barringer Crater in Arizona -- a giant hole almost 1.6 kilometers (1 mile) across and 175 meters (570 feet) deep.

Image to left: Arizona's Barringer Crater - also known as meteor crater - is one of the youngest and best-preserved impact craters on Earth. Credit: NASA

Planet-Sized Pizza?
Jupiter's moon Io is the most volcanically active body in our solar system. Active volcanoes constantly spew material onto Io's surface. The moon's bizarre, blotted yellowish surface looks more like a pepperoni pizza than like the cratered surfaces of the other moons in our solar system.

Black and White image of the heavily-crater surface of Saturn's moon, Mimas, including a massive 62-mile wide crater that dominates the moon's surface
Mega Crater
Saturn's moon Mimas sports a massive impact crater more than 130 kilometers (80 miles) across and 5 kilometers (3 miles) deep. The battered moon is only 400 kilometers (250 miles) across. A crater of the same proportion on Earth would cover the entire United States.

Image to right: Voyager 1 took this image of Saturn's moon Mimas in 1980. Credit: NASA

Is That Planet Flirting?
Uranus' rings were discovered by accident. Two teams set up to watch a bright star pass behind Uranus -- this is a way to peek at the planet's atmosphere. They were surprised when the star unexpectedly blinked out. Nine of Uranus' rings caused the star to wink at them as each ring in turn blocked the light of the star.

Today's Forecast: Windy, Wild and Weird
Neptune is our solar system's windiest world. Winds whip clouds of frozen methane across the planet at speeds of more than 2,000 kilometers/hour (1,200 miles/hour) -- close to the top speed of a U.S. Navy F/A-18 Hornet fighter jet. Earth's most powerful winds hit only about 400 kilometers/hour (250 miles/hour).

Bring a Flashlight
High noon on Pluto would look a lot like a moonlit night here on Earth. The sunlight that reaches Pluto is about 1,000 times dimmer than what we see here on Earth and provides little warmth.

Black and White image of the battered nucleus of comet Wild 2
Image above: Gravity wouldn't hinder an explorers trek across the battered surface of the nucleus of comet Wild 2. Credit: NASA
Hang On
If you weigh 45 kilograms (100 pounds) on Earth, you'd weigh only about 0.005 kilograms (0.01 pounds) on a comet. Although we don't recommend it, you could easily jump right off into space. If you rode a comet close to the Sun, you'd probably get blown into space on a jet of dust and gas.

Related Sites:
Extreme Space Facts
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Office of Space Science
Find this article at:
http://www.nasa.gov/audience/forstudents/5-8/features/F_Extreme_Planets_5-8.html