ScienceIQ.com

Hydrogen - The Simplest Element

Hydrogen is the simplest element; an atom consists of only one proton and one electron. It is also the most plentiful element in the universe. Despite its simplicity and abundance, hydrogen doesn't occur naturally as a gas on the Earth--it is always combined with other elements. Water, for example, is a combination of hydrogen and oxygen (H2O) ...

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Hydrogen
Geology

Glaciers: Rivers of Ice

Glaciers are massive sheets of ice that occur on every continent of the world except Australia. These giant ice slabs have a humble beginning, as the tiny snowflakes in winter precipitation that ... Continue reading

Glaciers
Mathematics

Picture This

What 3 dimensional shape will pass through a rectangle, triangle and circle each time filling the whole space? The answer may surprise you in it's simplicity. Before I tell you what it is, see if you ... Continue reading

PictureThis
Geology

Metamorphic Rock

There are three rock types on earth, named according to how the rock is formed. Igneous rock forms as it cools to a solid from molten rock. Sedimentary rock is formed from the consolidation of ... Continue reading

MetamorphicRock
Geology

Landslides and Mudflows

Landslides are a serious geologic hazard common to almost every state in the United States. It is estimated that nationally they cause up to $2 billion in damages and from 25 to 50 deaths annually. ... Continue reading

LandslidesandMudflows

The Brave and Cold Ulysses

TheBraveandColdUlyssesDeep space is cold. Very cold. That's a problem--especially if you're flying in an old spaceship. And your power supplies are waning. And the fuel lines could freeze at any moment. Oh, and by the way, you've got to keep flying for thirteen more years. It sounds like a science fiction thriller, but this is really happening to the spacecraft Ulysses. Ulysses was launched in 1990 on a five-year mission to study the sun. The craft gathered new data about the speed and direction of the solar wind. It discovered the 3D shape of the sun's magnetic field. It recorded solar flares on the sun, and super-solar flares from distant neutron stars. Ulysses even flew through the tail of comet Hyakutake, an unexpected encounter that delighted astronomers. The mission was supposed to end in 1995, but Ulysses was too successful to quit. NASA and the ESA have granted three extensions, most recently in Feb. 2004. Ulysses is scheduled to keep going until 2008, thirteen years longer than originally planned.

Ulysses' extended mission, as before, is to study the sun. But at the moment Ulysses is far from our star. It's having an encounter with Jupiter, studying the giant planet and its magnetic field. Sunlight out there is 25 times less intense than what we experience on Earth, and Ulysses is getting perilously cold. Back in the 1980's, when Ulysses was still on Earth and being assembled, mission planners knew that the spacecraft would have to endure some low temperatures. So they put dozens of heaters onboard, all powered by a Radioisotope Thermoelectric Generator, or

Fuel lines are critical to the mission. They deliver hydrazine propellant to the ship's eight thrusters. Every week or so, ground controllers fire the thrusters to keep Ulysses' radio antenna pointing toward Earth. The thrusters won't work if the hydrazine freezes. No thrusters means no communication. The mission would be lost. About eight meters of fuel line snake through the spaceship. Every twist and turn is a possible cold spot, a place where the hydrazine can begin to solidify. The temperature at any given point along the fuel lines is bewilderingly sensitive to what's going on elsewhere in the spacecraft. Turning on a scientific instrument