“NASA’s Curiosity rover surveyed its surroundings on August 9, 2018, producing a 360-degree panorama of its current location on Mars’ Vera Rubin Ridge. The panorama includes skies darkened by a fading global dust storm and a view from the Mast Camera of the rover itself, revealing a thin layer of dust on Curiosity’s deck. In the foreground is the rover’s most recent drill target, named “Stoer” after a town in Scotland near where important discoveries about early life on Earth were made in lakebed sediments.”
“Volcanic activity, or volcanism, has played a significant role in the geologic evolution of Mars. Scientists have known since the Mariner 9 mission in 1972 that volcanic features cover large portions of the Martian surface. These features include extensive lava flows, vast lava plains, and the largest known volcanoes in the Solar System. Martian volcanic features range in age from Noachian (>3.7 billion years) to late Amazonian (< 500 million years), indicating that the planet has been volcanically active throughout its history, and some speculate it probably still is so today. Both Earth and Mars are large, differentiated planets built from similar chondritic materials. Many of the same magmatic processes that occur on Earth also occurred on Mars, and both planets are similar enough compositionally that the same names can be applied to their igneous rocks and minerals.
Volcanism is a process in which magma from a planet’s interior rises through the crust and erupts on the surface. The erupted materials consist of molten rock (lava), hot fragmental debris (tephra or ash), and gases. Volcanism is a principal way that planets release their internal heat. Volcanic eruptions produce distinctive landforms, rock types, and terrains that provide a window on the chemical composition, thermal state, and history of a planet’s interior.
Magma is a complex, high-temperature mixture of molten silicates, suspended crystals, and dissolved gases. Magma on Mars likely ascends in a similar manner to that on Earth. It rises through the lower crust in diapiric bodies that are less dense than the surrounding material. As the magma rises, it eventually reaches regions of lower density. When the magma density matches that of the host rock, buoyancy is neutralized and the magma body stalls. At this point, it may form a magma chamber and spread out laterally into a network of dikes and sills. Subsequently, the magma may cool and solidify to form intrusive igneous bodies (plutons). Geologists estimate that about 80% of the magma generated on Earth stalls in the crust and never reaches the surface.
As magma rises and cools, it undergoes many complex and dynamic compositional changes. Heavier minerals may crystallize and settle to the bottom of the magma chamber. The magma may also assimilate portions of host rock or mix with other batches of magma. These processes alter the composition of the remaining melt, so that any magma reaching the surface may be chemically quite different from its parent melt. Magmas that have been so altered are said to be “evolved” to distinguish them from “primitive” magmas that more closely resemble the composition of their mantle source. More highly evolved magmas are usually felsic, that is enriched in silica, volatiles, and other light elements compared to iron- and magnesium-rich (mafic) primitive magmas. The degree and extent to which magmas evolve over time is an indication of a planet’s level of internal heat and tectonic activity. The Earth’s continental crust is made up of evolved granitic rocks that developed through many episodes of magmatic reprocessing. Evolved igneous rocks are much less common on cold, dead bodies such as the Moon. Mars, being intermediate in size between the Earth and the Moon, is thought to be intermediate in its level of magmatic activity.
The most common form of volcanism on the Earth is basaltic. Basalts are extrusive igneous rocks derived from the partial melting of the upper mantle. They are rich in iron and magnesium (mafic) minerals and commonly dark gray in color. The principal type of volcanism on Mars is almost certainly basaltic too. On Earth, basaltic magmas commonly erupt as highly fluid flows, which either emerge directly from vents or form by the coalescence of molten clots at the base of fire fountains (Hawaiian eruption). These styles are also common on Mars, but the lower gravity and atmospheric pressure on Mars allow nucleation of gas bubbles (see above) to occur more readily and at greater depths than on Earth. As a consequence, Martian basaltic volcanoes are also capable of erupting large quantities of ash in Plinian-style eruptions. In a Plinian eruption, hot ash is incorporated into the atmosphere, forming a huge convective column (cloud). If insufficient atmosphere is incorporated, the column may collapse to form pyroclastic flows. Plinian eruptions are rare in basaltic volcanoes on Earth where such eruptions are most commonly associated with silica-rich andesitic or rhyolitic magmas (e.g., Mount St. Helens).
Because the lower gravity of Mars generates less buoyancy forces on magma rising through the crust, the magma chambers that feed volcanoes on Mars are thought to be deeper and much larger than those on Earth. If a magma body on Mars is to reach close enough to the surface to erupt before solidifying, it must be big. Consequently, eruptions on Mars are less frequent than on Earth, but are of enormous scale and eruptive rate when they do occur. Somewhat paradoxically, the lower gravity of Mars also allows for longer and more widespread lava flows. Lava eruptions on Mars may be unimaginably huge. A vast lava flow the size of the state of Oregon has recently been described in western Elysium Planitia. The flow is believed to have been emplaced turbulently over the span of several weeks and thought to be one of the youngest lava flows on Mars.”
“The Dragon spacecraft was released from the Station’s robotic arm at 18:38 GMT on 3 August 2018. Thrusters fired to increase its distance from the Space Station and the spacecraft started its deorbit and return to Earth, splashing down in the Pacific Ocean less than seven hours after release. The International Space Station flies at 28 800 km/h above our planet doing a complete orbit in around 90 minutes – during release operations the sun set and rose above the horizon many times. As Dragon faded into the distance it flew over a stormy part of Earth – lightning flashes can be seen many kilometres below. Dragon is the only spacecraft that can return to Earth with scientific cargo aside from the Soyuz spacecraft that ferries astronauts to space and back – this flight carried over 1700 kg of cargo.
The International Space Station also released Cygnus supply spacecraft to burn up harmlessly over Earth. The spacecraft was released at 14:17 GMT on 15 July 2018 as the International Space Station flew over Colombia. Cygnus spent two weeks orbiting Earth on its own allowing engineers to conduct tests as well as releasing a series of miniature satellites before ending its mission.”
“The Ionospheric Connection Explorer (ICON) is a satellite designed to investigate changes in the Earth’s ionosphere. It is scheduled to be launched aboard a Pegasus XL rocket as part of NASA’s Explorers program and operated by UC Berkeley’s Space Sciences Laboratory. ICON will study the interaction between Earth’s weather systems and space weather driven by the Sun, and how this interaction drives turbulence in the upper atmosphere. It is hoped that a better understanding of this dynamic will mitigate its effects on communications, GPS signals, and technology in general.”
“On August 4th 2018 we successfully launched the Nexø II rocket. Nexø II is Copenhagen Suborbitals most advanced rocket to date. In this video we show you the complete story will all the highlights of the mission. ”
“NASA’s OSIRIS-REx asteroid sample return mission launched in 2016 and now (August, 2018) is entering its approach phase. OSIRIS-REx will arrive at asteroid Bennu in December, 2018. OSIRIS-REx will help unveil the mysteries of our solar system’s formation.”
Video Credit: NASA’s Goddard Space Flight Center/Katrina Jackson
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