Using information obtained from around a dozen earthquakes detected on Mars by the Very Broad Band SEIS seismometer, developed in France, the international team of NASA's InSight mission has unveiled the internal structure of Mars. The three papers published on July 23, provide, for the first time, an estimate of the size of the planet's core, the thickness of its crust and the structure of its mantle, based on the analysis of seismic waves reflected and modified by interfaces in its interior.
A new survey of our home galaxy, the Milky Way, combines the capabilities of the Very Large Array and the Effelsberg telescope in Germany to provide astronomers with valuable new insights into how stars much more massive than the Sun are formed.
A dust storm that engulfed Mars in 2018 destroyed a vortex of cold air around the planet's south pole and brought an early spring to the hemisphere. By contrast, the storm caused only minor distortions to the polar vortex in the northern hemisphere and no dramatic seasonal changes.
A team at the Natural History Museum (NHM), London is paving the way for future rovers to search for meteorites on Mars. The scientists are using the NHM's extensive meteorite collection to test the spectral instruments destined for the ExoMars rover Rosalind Franklin, and develop tools to identify meteorites on the surface of the red planet. The project is being presented today (23 July) at the virtual National Astronomy Meeting 2021.
New high-resolution observations clearly show a moon-forming region around exoplanet PDS 70c. The observations have allowed astronomers to determine the ring-shaped region's size and mass for the first time.
A new approach to analysing the development of magnetic tangles on the Sun has led to a breakthrough in a longstanding debate about how solar energy is injected into the solar atmosphere before being released into space, causing space weather events. The first direct evidence that field lines become knotted before they emerge at the visible surface of the Sun has implications for our ability to predict the behaviour of active regions and the nature of the solar interior.
According to the latest cosmological models, large spiral galaxies such as the Milky Way grew by absorbing smaller galaxies, by a sort of galactic cannibalism. Evidence for this is given by very large structures, the tidal stellar streams, which are observed around them, which are the remains of these satellite galaxies. But the full histories of the majority of these cases are hard to study, because these flows of stars are very faint, and only the remains of the most recent mergers have been detected.
Little is known about the weather at night on Venus as the absence of sunlight makes imaging difficult. Now, researchers have devised a way to use infrared sensors on board the Venus orbiter Akatsuki to reveal the first details of the nighttime weather of our nearest neighbor. Their analytical methods could be used to study other planets including Mars and gas giants as well.
Scientists show for the first time that 'stealth' coronal mass ejections, a type of solar storm, can be detected early on the Sun's surface. This could help put measures in place that limit damage to technology and energy grids on Earth from the electromagnetic radiation. The new techniques can be implemented immediately, and their power to forecast risky events will become even greater once the new Solar Orbiter and similar spacecraft become fully operational.
A team of solar physicists led by Laurent Gizon of the Max Planck Institute for Solar System Research (MPS) and the University of Goettingen in Germany has reported the discovery of global oscillations of the Sun with very long periods, comparable to the 27-day solar rotation period. The oscillations manifest themselves at the solar surface as swirling motions with speeds on the order of 5 kilometers per hour.