Showing 20 articles starting at article 301
< Previous 20 articles Next 20 articles >
Categories: Geoscience: Geomagnetic Storms, Space: The Solar System
Published Despite doubts from quantum physicists: Einstein's theory of relativity reaffirmed
(via sciencedaily.com) Original source One of the most basic assumptions of fundamental physics is that the different properties of mass -- weight, inertia and gravitation -- always remain the same in relation to each other. Although all measurements to date confirm the equivalence principle, quantum theory postulates that there should be a violation. This inconsistency between Einstein's gravitational theory and modern quantum theory is the reason why ever more precise tests of the equivalence principle are particularly important. A team has now succeeded in proving with 100 times greater accuracy that passive and active gravitational mass are always equivalent -- regardless of the particular composition of the respective masses.
Published Webb celebrates first year of science with close-up on birth of sun-like stars
(via sciencedaily.com) Original source From our cosmic backyard in the solar system to distant galaxies near the dawn of time, NASA's James Webb Space Telescope has delivered on its promise of revealing the universe like never before in its first year of science operations. To celebrate the completion of a successful first year, NASA has released Webb's image of a small star-forming region in the Rho Ophiuchi cloud complex.
Published New study reveals evidence of diverse organic material on Mars
(via sciencedaily.com) Original source Scientists gain vital insights into Mars' history and potential for supporting life.
Published New radar technique lets scientists probe invisible ice sheet region on Earth and icy worlds
(via sciencedaily.com) Original source A new radar technique developed by a graduate student allows imaging of the upper few feet of ice sheets on Earth and icy worlds. The technique uses instruments on airplanes or satellites to survey large regions quickly. The upper few feet of ice sheets are important for measuring melt on Earth or looking for habitable environments on icy worlds. Previous airborne or satellite techniques could not image this narrow region in detail.
Published Training robots how to learn, make decisions on the fly
(via sciencedaily.com) Original source Mars rovers have teams of human experts on Earth telling them what to do. But robots on lander missions to moons orbiting Saturn or Jupiter are too far away to receive timely commands from Earth. Researchers developed a novel learning-based method so robots on extraterrestrial bodies can make decisions on their own about where and how to scoop up terrain samples.
Published Satellite security lags decades behind the state of the art
(via sciencedaily.com) Original source Researchers have tested the software of three satellites. And they found many standard security mechanisms missing.
Published Gauging the strength of ancient and active rivers beyond Earth
(via sciencedaily.com) Original source A new technique allows scientists to see how intensely rivers used to flow on Mars, and how they currently flow on Titan. The method uses satellite observations to estimate the rate at which rivers move fluid and sediment downstream.
Published Why the day is 24 hours long: Astrophysicists reveal why Earth's day was a constant 19.5 hours for over a billion years
(via sciencedaily.com) Original source Astrophysicists have revealed how the slow and steady lengthening of Earth's day caused by the tidal pull of the moon was halted for over a billion years. They show that from approximately two billion years ago until 600 million years ago, an atmospheric tide driven by the sun countered the effect of the moon, keeping Earth's rotational rate steady and the length of day at a constant 19.5 hours. Without this billion-year pause in the slowing of our planet's rotation, our current 24-hour day would stretch to over 60 hours. The paper offers a new perspective on how global warming will affect the length of our day and validates global circulation models as a climate modelling tool.
Published Earth formed from dry, rocky building blocks
(via sciencedaily.com) Original source A new study shows that the so-called planetesimals that accreted together to form Earth must have been composed of dry, rocky materials.
Published Large sub-surface granite formation signals ancient volcanic activity on Moon's dark side
(via sciencedaily.com) Original source A large formation of granite discovered below the lunar surface likely was formed from the cooling of molten lava that fed a volcano or volcanoes that erupted early in the Moon's history -- as long as 3.5 billion years ago.
Published New image from James Webb Space Telescope reveals astonishing Saturn and its rings
(via sciencedaily.com) Original source Saturn's iconic rings seem to glow eerily in this incredible infrared picture, which also unveils unexpected features in Saturn's atmosphere. This image serves as context for an observing program that will test the telescope's capacity to detect faint moons around the planet and its bright rings. Any newly discovered moons could help scientists put together a more complete picture of the current system of Saturn, as well as its past.
Published Astrophysicists propose a new way of measuring cosmic expansion: Lensed gravitational waves
(via sciencedaily.com) Original source The universe is expanding; we've had evidence of that for about a century. But just how quickly celestial objects are receding from each other is still up for debate.
Published Gullies on Mars could have been formed by recent periods of liquid meltwater, study suggests
(via sciencedaily.com) Original source A study offers new insights into how water from melting ice could have played a recent role in the formation of ravine-like channels that cut down the sides of impact craters on Mars.
Published Life after death: Astronomers find a planet that shouldn't exist
(via sciencedaily.com) Original source The star would have inflated up to 1.5 times the planet's orbital distance -- engulfing the planet in the process -- before shrinking to its current size at only one-tenth of that distance.
Published Magnetic bacteria point the way
(via sciencedaily.com) Original source Magnetotactic bacteria, which can align with the Earth's magnetic field, have been discovered in a new location. Previously observed on land and in shallow water, analysis of a hydrothermal vent has proven that they can also survive deep under the ocean. The bacteria were able to exist in an environment that was not ideal for their typical needs. Magnetotactic bacteria are of interest not only for the role they play in Earth's ecosystem, but also in the search for extraterrestrial life. Evidence of their existence can remain in rocks for billions of years. Their magnetic inclinations can also provide a record of how magnetic poles have shifted over time. This new discovery brings hope to researchers that the magnetic bacteria might be found in yet more unexpected locations, on Earth and perhaps even on Mars or beyond.
Published Molecular filament shielded young solar system from supernova
(via sciencedaily.com) Original source Isotope ratios found in meteorites suggest that a supernova exploded nearby while the Sun and Solar System were still forming. But the blast wave from a supernova that close could have potentially destroyed the nascent Solar System. New calculations shows that a filament of molecular gas, which is the birth cocoon of the Solar System, aided the capture of the isotopes found in the meteorites, while acting as a buffer protecting the young Solar System from the nearby supernova blast.
Published Detection of an echo emitted by our Galaxy's black hole 200 years ago
(via sciencedaily.com) Original source An international team of scientists has discovered that Sagittarius A* (Sgr A*), the supermassive black hole at the centre of the Milky Way, emerged from a long period of dormancy some 200 years ago. The team, led by Frédéric Marin, a CNRS researcher at the Astronomical Strasbourg Observatory (CNRS/University of Strasbourg), has revealed the past awakening of this gigantic object, which is four million times more massive than the Sun. Their work is published in Nature on 21 June.
Published Exoplanet may reveal secrets about the edge of habitability
(via sciencedaily.com) Original source How close can a rocky planet be to a star, and still sustain water and life? A recently discovered exoplanet may be key to solving that mystery.
Published Jupiter's moon Europa may have had a slow evolution
(via sciencedaily.com) Original source Europa may have a metamorphic origin for the ocean. While some scientists speculated this, a research team shows that if Europa indeed formed from hydrated rocks (i.e., rocks have hydrogen and oxygen), then enough of Europa's interior should get hot enough to release water directly from the hydrated rocks to form the ocean and ice shell.
Published Researchers demystify the unusual origin of the Geminids meteor shower
(via sciencedaily.com) Original source Princeton researchers used observations from NASA's Parker Solar Probe mission to deduce that it was likely a violent, catastrophic event -- such as a high-speed collision with another body or a gaseous explosion -- that created the Geminids meteoroid stream. Mysteries surrounding the origin of the Geminids have long fascinated scientists because, while most meteor showers are created when a comet emits a tail of ice and dust, the Geminids stem from an asteroid -- a chunk of rock that normally does not produce a tail. Until now, this unusual meteoroid stream had only been studied from Earth.