You won't need a time machine to know what Earth's weather was like billions of years ago. Climate data from Jupiter and Saturn can provide insight to our own planet's past and future atmospheric conditions, an expert from the University of Houston said.
Assistant Professor Liming Li is leading a team of scientists from the University of Wisconsin-Madison and NASA's Jet Propulsion Laboratory to analyze data from instruments on board the Cassini. The spacecraft is currently on a mission to explore Saturn's systems.
NASA's Planetary Science Division awarded Li and his colleagues with two new projects worth $700,000 for the chance to study climate in other planets thru Cassini.
Cassini contains 12-gathering instruments that can give scientists access to insurmountable amount of data. The spacecraft's primary mission was supposed to end in 2008, but because it was so successful, NASA extended it several times. It is now scheduled to end next year.
Titan's Atmosphere
The research team will be calculating the energy budget for Jupiter, Saturn and Saturn's moon Titan, because it will impact our understanding of planetary evolution and climate.
The energy budget accounts for the amount of energy from the sun that comes into a planet's climate system and how much energy is emitted.
On Earth, Li said the incoming energy is approximately equal to the outgoing energy. The temperature does not dramatically change, even with the effects of greenhouse gases.
On the other hand, Saturn and Jupiter emit more energy than the energy they absorb, thus generating internal heat. Titan and Earth are similar, Li said, because they do not have significant internal heat.
Li said scientists believe that the atmosphere in Titan is like the ancient atmosphere on our own planet. By studying the Saturn satellite's atmosphere, we can learn what occurred in the past to Earth's atmosphere.
Seasons Change
Each year in Saturn is approximately equivalent to 30 Earth years. Li said this meant that long-term observations are needed to learn about the ringed planet's seasons.
"Fortunately, Cassini is a long-term mission, gathering data for more than 10 years," said Li. "Every year, every day, we are getting beautiful data from the spacecraft."
According to Li, Saturn's atmospheric systems vary as seasons change. In summer and spring, there are giant storms. Scientists have even observed the largest storm in our solar system through Cassini.
"It was 100,000 kilometers wide, which is more than 62,000 miles," said Li. "That is much bigger than a storm on Earth and, actually, bigger than Earth."
Why is it so important? It's because atmospheric scientists will have the chance to look at climate change in a short-term scale. With data from Cassini beginning in 2004 up until 2017, the observations will cover changes within two to three seasons.
Since our planet and Saturn have almost the same rotation angle, it is likely that they have some similar changes in seasons. Before this mission, however, the team did not have any data to help them study the ringed planet's seasons, so Cassini's findings are quite remarkable.
Crossing Over
Li began his career in meteorology in China and concerned himself with weather conditions on our own planet. He came to the United States for his Ph.D. and became interested in planetary science, studying meteorology in other planets.
The physics associate professor has been actively involved in ongoing space missions that explore giant planets in our solar system. He said the weather system in other planets is completely different from our own.
"By studying the weather systems on planets, we can get a wide perspective for how the climate changes on Earth," added Li.
