Atmospheres

Parker Solar Probe: NASA's Mission to Touch the Sun

Professor Joe Giacalone, Co-Investigator for the Integrated Science Investigation of the Sun (IS☉IS) instrument on Parker Solar Probe. The Parker Solar Probe will swoop to within 4 million miles of the sun's surface, facing heat and radiation like no spacecraft before it. Launching in 2018, Parker Solar Probe will provide new data on solar activity and make critical contributions to our ability to forecast major space-weather events that impact life on Earth.

Date
Presenter(s)
Object(s)
Mission(s)/Instrument(s)

Storms, Lakes & the Methane Cycle on Titan Lure us with Earth-like Qualities to an Exotic World

Titan’s surface appears familiar. We recognize the lakes that resemble those on Earth, along with channels indicative of rainfall. In addition we find washes like those in Arizona and dunes reminiscent of Namibia, Africa, which are shaped by weather. These terrestrial-like features result from Titan’s unique resemblance to Earth. In Titan’s atmosphere, the second most abundant gas in the atmosphere is methane, which, like water on Earth, exists as a gas, liquid and ice, and cycles between the atmosphere and surface. Similar to Earth’s hydrological cycle, Titan sports clouds, rain, and lakes. Yet, Titan’s cycle differs dramatically from its terrestrial counterpart, and reveals the workings of weather in an atmosphere that is ten times thicker than Earth’s atmosphere, that is two orders of magnitude less illuminated, and that involves a different condensable. Recently Titan has been explored in great detail with measurements conducted on Titan’s surface (by the Huygens Probe) and by ongoing remote observations from Cassini and ground-based telescopes. Now at the end of Cassini's Mission, we find that Titan's weather, climate and surface-to-atmosphere exchange of volatiles vastly differs from the manifestation of these processes on Earth, largely as a result of different basic characteristics of these planetary bodies. This talk compares Titan and Earth's lower atmospheres, with the aim to understand the processes that control weather on each planetary body. We will conclude by entertaining the puzzling question of how Titan acquired and retains the methane in its atmosphere, which underlies the similarities of Titan and Earth.

Topic(s)
Date
Presenter(s)
Object(s)
Mission(s)/Instrument(s)

Visiting Our Sun: Unraveling the Mysteries of the Solar Atmosphere using Parker Solar Probe

Since the start of the space age we have been able to measure the solar wind, a hot and tenuous plasma emanating from the Sun's surface that fills the solar system. We have not been able to determine what mechanisms are responsible for accelerating this wind, nor why the Sun's atmosphere is hotter than its surface, an issue known as the coronal heating problem. One of the main limitations on our ability to answer these questions is that we have yet to directly measure the solar wind near the Sun. In August of 2018, NASA launched Parker Solar Probe (PSP), a mission that will provide for the first time direct observations of the corona. Over its seven year mission, PSP will orbit the Sun at increasingly close distances, down to less than four million miles from the Sun's surface, seven times closer than any previous mission. We will discuss how these measurements are being made, what theories are being tested, and what benefits better understanding the Sun's behavior will bring to society.

Topic(s)
Date
Presenter(s)
Object(s)
Mission(s)/Instrument(s)

Ice Cores and Climate on an Alien World

Thousands of Earth-like planets around other stars will soon be known, but the Earth could be unusual and not make a good comparison. Earth’s climate is so complicated that despite decades of space-based observations and ice-core analysis we only recently discovered how drastically it’s changing. Mars offers another Earth-like climate without the complicating effects of oceans, life and human activity, but still possessing ice caps that record its climate. Studying Mars’ climate record, with the tools we’ve developed here on Earth, helps us understand the climate of Earth-like planets both in our solar system and throughout the galaxy. The University of Arizona continues to play a leading role in exploring Mars ice and climate through our past and present spacecraft instruments and missions. I’ll describe the progress we’ve made and our future exploration directions.

Date
Presenter(s)
Object(s)
Mission(s)/Instrument(s)