Kids ask: Will astronauts travel to Jupiter?

Students in Elise Diaz's fifth-grade class at O'Plaine Elementary School in Gurnee asked, “Will astronauts ever travel to a gas planet?”

Astronauts have traveled to from Earth to the moon, a distance of about 225,000 miles. That's a short hop when compared to a trip from the Earth to the nearest gas planet, Jupiter, or nearly 400 million miles.

Geza Gyuk, director of Chicago's Adler Planetarium, says a more realistic objective at this time might be to send people to Mars or to an asteroid that's close to Earth.

“It'll take a couple decades until we have solved the engineering issues that'll let us get to Mars,” Gyuk said. “Mars varies between 50 (million) and 250 million miles away from the Earth. Using current rockets, a trip to Mars will probably take about nine months.”

Most travelers might take a pass on an all-expenses paid trip to Jupiter. With current technology, it would probably be a one-way trip. The planet has hardly any oxygen; the temperature at its lowest is around -150 degrees Fahrenheit; its clouds contain poisonous ammonia ice; it has violent storms that are bigger than the size of our whole planet.

“Even a brief few-minute passage through the planet's radiation belts would likely be fatal,” Gyuk said.

Today's rockets just don't carry enough power to drive manned spacecraft that far or to land in the gaseous atmosphere once they arrive. Plus, Jupiter is missing something important — a surface to land a spacecraft. Even worse, the return trip from the clouds of Jupiter would be next to impossible.

At great risk, scientists have sent a robotic probe on a one-way trip to Jupiter.

“In December, 1995, the Galileo atmospheric entry probe slammed into the atmosphere of Jupiter at almost 50 kilometers per second,” Gyuk said. “Slowing down, the probe had to survive more than 200 times the normal force of gravity. It dropped through the atmosphere for about an hour and reached a depth of about 100 miles below the cloud tops before being destroyed by the high pressures — 23 times that on the surface of Earth — and temperatures — more than 300 degrees Fahrenheit.”

There are three more gas planets in our solar system — Saturn, Uranus and Neptune — each even farther away than Jupiter.

“Astronomers know of many gas giant planets that circle other stars,” Gyuk said. “Those are way too far away for astronauts to reach anytime soon. Maybe someday in the very distant future, but right now traveling many light-years is not something that is we know how to do in any reasonable amount of time.”