The mesopause is the point of minimum temperature at the boundary between the mesosphere and the thermosphere atmospheric regions. Due to the lack of solar heating and very strong radiative cooling from carbon dioxide, the mesosphere is the coldest region on Earth with temperatures as low as -100 °C. The altitude of the mesopause for many years was assumed to be at around 85 km (53 mi), but observations to higher altitudes and modeling studies in the last 10 years have shown that in fact there are two mesopauses - one at about 85 km and a stronger one at about 100 km (62 mi), with a layer of slightly warmer air between them.
A solar flare is a relatively intense, localized emission of electromagnetic radiation in the Sun's atmosphere. Flares occur in active regions and are often, but not always, accompanied by coronal mass ejections, solar particle events, and other eruptive solar phenomena. The occurrence of solar flares varies with the 11-year solar cycle.
The Schumann resonances (SR) are a set of spectrum peaks in the extremely low frequency portion of the Earth's electromagnetic field spectrum. Schumann resonances are global electromagnetic resonances, generated and excited by lightning discharges in the cavity formed by the Earth's surface and the ionosphere.
The atmosphere of Mars is the layer of gases surrounding Mars. It is primarily composed of carbon dioxide (95%), molecular nitrogen (2.85%), and argon (2%). It also contains trace levels of water vapor, oxygen, carbon monoxide, hydrogen, and noble gases. The atmosphere of Mars is much thinner and colder than Earth's having a max density 20g/m3 with a temperature generally below zero down to -60 Celsius. The average surface pressure is about 610 pascals (0.088 psi) which is 0.6% of the Earth's value.
An ejecta blanket is a generally symmetrical apron of ejecta that surrounds an impact crater; it is layered thickly at the crater's rim and thin to discontinuous at the blanket's outer edge. The impact cratering is one of the basic surface formation mechanisms of the solar system bodies and the formation and emplacement of ejecta blankets are the fundamental characteristics associated with impact cratering event. The ejecta materials are considered as the transported materials beyond the transient cavity formed during impact cratering regardless of the state of the target materials.
The atmosphere of Venus is the very dense layer of gasses surrounding the planet Venus. Venus's atmosphere is composed of 96.5% carbon dioxide and 3.5% nitrogen, with other chemical compounds present only in trace amounts. It is much denser and hotter than that of Earth; the temperature at the surface is 740 K, and the pressure is 93 bar (1,350 psi), roughly the pressure found 900 m (3,000 ft) under water on Earth. The atmosphere of Venus supports decks of opaque clouds of sulfuric acid that cover the entire planet, preventing optical Earth-based and orbital observation of the surface. Information about surface topography has been obtained exclusively by radar imaging.
Heimdal is a relatively recent impact crater on the planet Mars. It is a simple crater which lies in Vastitas Borealis, the northern plain. It is named after the Norwegian town of Heimdal.
MAVEN is a NASA spacecraft orbiting Mars to study the loss of that planet's atmospheric gases to space, providing insight into the history of the planet's climate and water. The name is an acronym for "Mars Atmosphere and Volatile Evolution" while the word maven also denotes "a person who has special knowledge or experience; an expert". MAVEN was launched on an Atlas V rocket from Cape Canaveral Air Force Station, Florida, on 18 November 2013 UTC and went into orbit around Mars on 22 September 2014 UTC. The mission is the first by NASA to study the Mars atmosphere. The probe is analyzing the planet's upper atmosphere and ionosphere to examine how and at what rate the solar wind is stripping away volatile compounds.
The gravity of Mars is a natural phenomenon, due to the law of gravity, or gravitation, by which all things with mass around the planet Mars are brought towards it. It is weaker than Earth's gravity due to the planet's smaller mass. The average gravitational acceleration on Mars is 3.72076 m/s2 and it varies.
Maura E. Hagan is a Professor Emeritus of Physics and a former Dean of the College of Science at Utah State University. She is a Fellow of both the American Meteorological Society and the American Geophysical Union, and was elected a member of the National Academy of Sciences in 2019.
Nancy U. Crooker is an American physicist and professor emerita of space physics at Boston University, Massachusetts. She has made major contributions to the understanding of geomagnetism in the Earth's magnetosphere and the heliosphere, particularly through the study of interplanetary electrons and magnetic reconnection.
The Whole Atmosphere Community Climate Model (WACCM) is used to generate computer simulations of the dynamic processes interacting between the terrestrial and solar systems that impact on Earth's climate. The original model was developed around the turn of the millennium with the most recent iteration, version 6 (WACCM6), released in 2019. The Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X) extends the model to space weather and space climate.
Laura J. Pyrak-Nolte is an American geophysicist who is Distinguished Professor of Physics and Astronomy at Purdue University. She is the former President of the International Society of Porous Media and former President of the American Rock Mechanics Association. In 2020 Pyrak-Nolte was awarded the Society of Exploration Geophysicists Reginald Fessenden Award. She is a Fellow of the American Geophysical Union.
M. Joan Alexander is an atmospheric scientist known for her research on gravity waves and their role in atmospheric circulation.
Marine geophysics is the scientific discipline that employs methods of geophysics to study the world's ocean basins and continental margins, particularly the solid earth beneath the ocean. It shares objectives with marine geology, which uses sedimentological, paleontological, and geochemical methods. Marine geophysical data analyses led to the theories of seafloor spreading and plate tectonics.
Cora Einterz Randall is an atmospheric scientist known for her research on particles in the atmosphere, particularly in polar regions.
Jennifer Logan is an atmospheric scientist known for her research on how human activities influence the atmosphere, particularly with respect to biomass burning and the ozone hole.
Patricia Reiff is an American space physicist at Rice University, known for her research on space weather and for engaging the public about science.
Janet Kozyra is a heliophysicist who works on solar superstorms. She has used data from Imager for Magnetopause to Aurora Global Exploration (IMAGE), to show that Earth interacts with solar energy during solar storms.
The magnetic field of Mars is the magnetic field generated from Mars's interior. Today, Mars does not have a global magnetic field. However, Mars did power an early dynamo that produced a strong magnetic field 4 billion years ago, comparable to Earth's present surface field. After the early dynamo ceased, a weak late dynamo was reactivated ~3.8 billion years ago. The distribution of Martian crustal magnetism is similar to the Martian dichotomy. Whereas the Martian northern lowlands are largely unmagnetized, the southern hemisphere possesses strong remanent magnetization, showing alternating stripes. Scientific understanding of the evolution of the magnetic field of Mars is based on the combination of satellite measurements and Martian ground-based magnetic data.
