Comets visit the inner Solar System, and leave without saying goodbye. Maybe they leave a trail of dust behind, and when the Earth passes through it, we get a pretty light show in the night sky, in the form of a meteor shower. Likewise, asteroids frequently go whizzing by, though they don’t leave us with a pyrotechnic display.
Sometimes these rocky interlopers head straight for Earth. And when they do, the results can be cataclysmic, like when an asteroid struck Earth about 66 million years ago, wiping out the dinosaurs and 75% of life on Earth. Other times, it’s not quite as cataclysmic, but still devastating, like in about 2350 BC, when debris from a disintegrating comet may have caused the collapse of an ancient empire.
But regardless of the severity of any of these individual events, the conclusion is crystal clear: Earth’s history is intertwined with the coming and going of space rocks. The evidence is all around us, sort of.
Continue reading “Ancient Meteorites Can be Found Embedded in Rocks, Like Fossils”
Satellite engineers know what every photographer knows: get close to your subject to get better pictures. Not just visible light pictures, but all across the spectrum. The lower altitude also improves things like radar, lidar, communications, and gps.
But when your subject is Earth, and Earth is surrounded by an atmosphere, getting closer is a delicate dance with physics. The closer a satellite gets to Earth, the more atmospheric drag it encounters. And that can mean an unscheduled plummet to destruction for Earth-Observing (EO) satellites.
Continue reading “Earth Observation Satellites Could be Flown Much Lower than Current Altitudes and Do Better Science”
Before our Solar System had planets, it had planetesimals. Scientists think that most of the meteorites that have struck Earth are fragments of these planetesimals. Scientists also think that these planetesimals either melted completely, very early in their history, or that they remained as little more than collections of rocks, or “rubble piles.”
But one family of meteorites, that have been found spread around the world, appear to come from a planetesimal that bucked that trend.
Continue reading “A Group of Meteorites All Came From a Destroyed Planetesimal With a Magnetic Core”
The United States and Russia/USSR have been adversaries for a long time. Their heated rivarly stretches back to the waning days of WW2, when the enormous Red Army was occupying large swathes of eastern Europe, and the allies recognized the inherent threat.
The Cold War followed, when the two nations aimed an absurd number of nuclear warheads at each other. Then came the Space Race, when both nations vied for the prestige of making it to the Moon.
The US won that race, but the rivalry didn’t cool down.
Continue reading “Russia Just Tested an Anti-Satellite Weapon”
The newest branch of the US Military has a logo and a motto now. The mottos is Semper Supra, meaning ‘Always Above’. The logo’s main feature is a delta wing design.
Continue reading “Here’s the New Space Force Logo”
Like all other technologies, satellite technology has grown in leaps and bounds in the past couple decades. Satellites can monitor Earth in increasingly high resolutions, aiding everything from storm forecasting, to climate change monitoring, to predicting crop harvests. But there’s one thing still holding satellites back: altitude.
Continue reading “This is What an Air-Breathing Electric Thruster’s Intake Would Look Like”
Earth’s lithosphere is made up of seven large tectonic plates and a number of smaller ones. The theory of plate tectonics that describes how these plates move is about 50 years old. But there’s never really been an understanding of how this system developed, and how the Earth’s shell split into separate plates and started moving.
Now a group of researchers have a possible explanation.
Continue reading “What Cracked the Earth’s Outer Shell and Started its Plate Tectonics?”
Natural processes here on Earth continually re-shape the planet’s surface. Craters from ancient asteroid strikes are erased in a short period of time, in geological terms. So how can researchers understand Earth’s history, and how thoroughly it may have been pummeled by asteroid strikes?
Scientists can turn their attention to our ancient companion, the Moon.
Continue reading “800 Million Years Ago, it Was Raining Asteroids on the Earth and Moon”
Landsat 8 strikes again.
Landsat 8 is the United States Geological Survey’s most recently launched satellite, and it holds the powerful Operational Land Imager (OLI.) The OLI is a powerful multi-spectral imager with a wide dynamic range.
The OLI does a great job of keeping an eye on Earth, and now its captured images of winds in Namibia picking dust up and carrying it out over the Atlantic Ocean.
Continue reading “Dust Seen Streaming Out of Namibia Into the Atlantic Ocean”
We’ve detected thousands of exoplanets, but for the most part, nobody’s ever seen them. They’re really just data, and graphs of light curves. The exoplanet images you see here at Universe Today and other space websites are the creations of very skilled illustrators, equal parts data and creative license. But that’s starting to change.
The European Southern Observatory’s Very Large Telescope (VLT) has captured images of two exoplanets orbiting a young, Sun-like star.
Continue reading “Wow! An Actual Picture of Multiple Planets Orbiting a Sunlike Star”