This image shows eroded channels near the Martian poles filled with bright frozen carbon dioxide, in contrast to the muted red of the underlying ground. Credit:NASA/JPL/University of Arizona
In the 17th century, astronomers Giovanni Domenica Cassini and Christian Huygens noted the presence of hazy white caps while studying the Martian polar regions. These findings confirmed that Mars had ice caps in both polar regions, similar to Earth. By the 18th century, astronomers began to notice how the size of these poles varied depending on where Mars was in its orbital cycle. Along with discovering that Mars’ axis was tilted like Earth’s, astronomers realized that Mars’ polar ice caps underwent seasonal changes, much like Earth’s.
While scientists have been aware that Mars’ polar ice caps change with the seasons, it has only been within the last 50 years that they have realized that they are largely composed of frozen carbon dioxide (aka. “dry ice”) that cycles in and out of the atmosphere – and questions as to how this happens remain. In a recent study, a team of researchers led by the Planetary Science Institute (PSI) synthesized decades of research with more recent observations of the poles. From this, they determined how the Martian poles differ in terms of their seasonal accumulation and release of atmospheric carbon dioxide.
Mars’ south polar ice cap. Credit: ESA / DLR / FU Berlin /
Ever since 1971, when theMariner 9 probe surveyed the surface of Mars, scientists have theorized that there might be subsurface ice beneath the southern polar ice cap on Mars. In 2004, the ESA’s Mars Express orbiter further confirmed this theory when its Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument detected what looked like water ice at a depth of 3.7 km (2.3 mi) beneath the surface.
These findings were very encouraging since they indicated that there could still be sources of liquid water on Mars where life could survive. Unfortunately, after reviewing the MARSIS data, a team of researchers led from Arizona State University (ASU) has proposed an alternative explanation. As they indicated in a recent study, the radar reflections could be the result of clays, metal-bearing minerals, or saline ice beneath the surface.
Lakes on Earth are a common sight in many locales. They’re central to the recreation and livelihood of millions of people. Few of those people think of the hydrodynamics that happen in a lake system. It is common for lakes to stratify into different layers. On Earth that stratification is the result of the sun heating the upper layer of water, which then becomes less dense and floats on top of the colder, more dense layer beneath it. Now, scientists from the Planetary Science Institute (PSI) have found similar dynamic cycles in a different kind of lake – the ethane and methane lakes on Titan.
Doom Mons and Sotra Patera, apparent cryovolcanic features on Titan. Credit: NASA/JPL
On Sept. 15th, 2017, NASA’s Cassini Orbiterconcluded its mission by diving into Saturn’s atmosphere. Over the course of the 13 years it spent studying the Saturn system, it revealed a great deal about this gas giant and its largest moon, Titan. In the coming years, scientists are eager to send another mission to Titan to follow up on Cassini and get a better look at its surface features, methane lakes, and other curious properties.
These include the morphological features in the northern polar region that are strikingly similar to volcanic features here on Earth. According to a recent study by the Planetary Science Institute (PSI), these features could be evidence of cryovolcanism that continues to this day. These findings are the latest evidence that Titan has an interior ocean and internal heating mechanisms, which could also mean the planet harbors life in his interior.
NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft celebrated one Earth year in orbit around Mars on Sept. 21, 2015. MAVEN was launched to Mars on Nov. 18, 2013 from Cape Canaveral Air Force Station in Florida and successfully entered Mars’ orbit on Sept. 21, 2014. Credit: NASA
Billions of years ago, Mars was once a much different place than the cold and desiccated place it is today. Basically, it had a thicker, warmer atmosphere and liquid water flowing on its surface, and maybe even life! The reason for this is because, like Earth, Mars had a planetary magnetic field that was generated by action in its core. But when that field disappeared, things began to change drastically!
For years, scientists believed that this field disappeared over 4 billion years ago, causing Mars’ atmosphere to be slowly stripped away by solar wind. But according to new research led by the University of British Columbia (UBC) has placed new constraints on when this magnetic field disappeared, indicating that Mars’ magnetic field existed sooner (and laster hundreds of millions of years longer) than previously thought.
Jeff Morgenthaler, a senior scientist at the Planetary Science Institute, likes to think of himself as an experimental physicist whose laboratory opens to the sky. He has used a comet to measure the ionization lifetime of carbon, is using Io’s atmosphere as a probe of conditions in Jupiter’s magnetosphere and has constructed a small-aperture coronagraph to monitor measure Jupiter’s magnetospheric response to a large volcanic eruption on Io.
Artist rendering of the XCOR Lynx outfitted with the Atsa Suborbital Observatory. Credit: XCOR
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Commercial space company XCOR Aerospace has signed a “Memorandum of Understanding” with the Planetary Science Institute, laying the groundwork for flying a human-operated telescope on board XCOR’s Lynx spacecraft. The Atsa Suborbital Observatory is a specially designed telescope for use in suborbital space vehicles, and when used with commercial suborbital vehicles, PSI says it will provide low-cost space-based observations above the contaminating atmosphere of Earth, while avoiding some operational constraints of satellite telescope systems.
“The XCOR vehicle design and capabilities work well for hosting the kind of observing facility we are developing,” said PSI Senior Scientist Faith Vilas, the Atsa Project Scientist.
“NASA has been flying suborbital observatories for decades, on unmanned, disposable rockets. The new manned, reusable commercial platforms will allow us to make repeated observations with a single instrument, but without the need to refurbish it between flights,” said Luke Sollitt, and affiliate scientist with PSI and a co-inventor with Vilas of the Atsa Observatory. “In addition, the short turn-around means we can do many observations or targets.”
Atsa means “eagle” in the Navajo language. The facility is optimized for observing solar system objects near the sun that are difficult to study from orbital observatories such as Hubble and ground-based telescopes.
The Lynx flight profile. Credit: XCOR
The Lynx is a two-seat, piloted space transport vehicle, capable of taking humans and payloads on a half-hour suborbital flight to 100 km (330,000 feet) and then return safely to a landing at the takeoff runway, providing 4-6 minutes of weightless flight.
Like an aircraft, Lynx is a horizontal takeoff and horizontal landing vehicle, but instead of a jet or piston engine, Lynx uses its own fully reusable rocket propulsion system to depart a runway and return safely.
The Atsa Observatory will be mounted on the top of the Lynx in an experiment pod. XCOR or PSI did not release the cost per flight, but XCOR’s price for one passenger is $95,000 USD. In contrast, the price for using sounding rockets vary, depending on how high the rocket goes, but some cost as little as $10,000 USD.
“These are natural targets for instruments on suborbital rockets to observe, but a human-tended facility using the kind of reusable launch vehicle offered by XCOR offers significant cost savings,” said Mark Sykes, CEO and Director of PSI, who is also a long-time planetary astronomer and is training to be an Atsa operator.
The Lynx spacecraft will fly to space on a customized flight trajectory and will be capable of precision pointing, allowing the Atsa system with its operator to acquire the desired target and make the planned observations. “We are being approached by many potential customers who are interested in supporting observations of the inner solar system,” Vilas said. “We will also be able to support target of opportunity observations for newly discovered objects and other phenomena.”
“We’re looking forward to flying PSI’s Atsa system on Lynx, it will be a groundbreaking experience. The rapid and flexible operations of the Lynx will enable scientists to pick specific targets of interest and the same day fly multiple tailor made observation missions quickly and inexpensively when they want them to be flown,” said Khaki Rodway McKee, XCOR’s Program Manager.
“We are entering into a new era in the human exploration of space, where private companies like XCOR and PSI will begin to play leading roles in certain areas, beginning with suborbital flight – harkening back to the days of NASA’s Mercury program,” Sykes said.
Andrew Nelson, XCOR’s Chief Operating Officer, said, “Much like the early days of the Internet, mobile communications and social networking revolutions saw new and innovative applications drive commercial multi-billion dollar marketplaces, so we are seeing privately funded efforts like PSI’s Atsa as a key early adopter signaling a robust future for suborbital reusable launch vehicles.”
