new like on March 21, 2021 at 10:15PM

Video: Perseverance Landing on Mars

What would it look like to land on Mars? To better monitor the instruments involved in the Entry, Decent, and Landing of the Perseverance Rover on Mars last week, cameras with video capability were included that have now returned their images. The featured 3.5-minute composite video begins with the opening of a huge parachute that dramatically slows the speeding spacecraft as it enters the Martian atmosphere. Next the heat shield is seen separating and falls ahead. As Perseverance descends, Mars looms large and its surface becomes increasingly detailed. At just past 2-minutes into the video, the parachute is released and Perseverance begins to land with dust-scattering rockets. Soon the Sky Crane takes over and puts Perseverance down softly, then quickly jetting away. The robotic Perseverance rover will now begin exploring ancient Jezero Crater, including a search for signs that life once existed on Earth’s neighboring planet. via NASA

Stars over an Erupting Volcano

Mt. Etna has been erupting for hundreds of thousands of years. Located in Sicily, Italy, the volcano produces lava fountains over one kilometer high. Mt. Etna is not only one of the most active volcanoes on Earth, it is one of the largest, measuring over 50 kilometers at its base and rising nearly 3 kilometers high. Pictured erupting last month, a lava plume shoots upwards, while hot lava flows down the volcano’s exterior. Likely satellite trails appear above, while ancient stars dot the sky far in the distance. This volcanic eruption was so strong that nearby airports were closed to keep planes from flying through the dangerous plume. The image foreground and background were captured consecutively by the same camera and from the same location. via NASA

A Flag Shaped Aurora over Sweden

It appeared, momentarily, like a 50-km tall banded flag. In mid-March of 2015, an energetic Coronal Mass Ejection directed toward a clear magnetic channel to Earth led to one of the more intense geomagnetic storms of recent years. A visual result was wide spread auroras being seen over many countries near Earth’s magnetic poles. Captured over Kiruna, Sweden, the image features an unusually straight auroral curtain with the green color emitted low in the Earth’s atmosphere, and red many kilometers higher up. It is unclear where the rare purple aurora originates, but it might involve an unusual blue aurora at an even lower altitude than the green, seen superposed with a much higher red. Now past Solar Minimum, colorful nights of auroras over Earth are likely to increase. via NASA

Perseverance Takes a Spin

After arriving at Jezero Crater on Mars, Perseverance went for a spin on March 4. This sharp image from the car-sized rover’s Navcam shows tracks left by its wheels in the martian soil. In preparation for operations on the surface of the Red Planet, its first drive lasted about 33 minutes. On a short and successful test drive Perseverance moved forward 4 meters, made a 150 degree turn, backed up for 2.5 meters, and now occupies a different parking space at its newly christened Octavia E. Butler Landing location. Though the total travel distance of the rover’s first outing was about 6.5 meters (21 feet), regular commutes of 200 meters or more can be expected in the future. via NASA

Three Tails of Comet NEOWISE

What created the unusual red tail in Comet NEOWISE? Sodium. A spectacular sight back in the summer of 2020, Comet NEOWISE, at times, displayed something more than just a surprisingly striated white dust tail and a pleasingly patchy blue ion tail. Some color sensitive images showed an unusual red tail, and analysis showed much of this third tail’s color was emitted by sodium. Gas rich in sodium atoms might have been liberated from Comet NEOWISE’s warming nucleus in early July by bright sunlight, electrically charged by ultraviolet sunlight, and then pushed out by the solar wind. The featured image was captured in mid-July from Brittany, France and shows the real colors. Sodium comet tails have been seen before but are rare — this one disappeared by late July. Comet C/2020 F3 (NEOWISE) has since faded, lost all of its bright tails, and now approaches the orbit of Jupiter as it heads back to the outer Solar System, to return only in about 7,000 years. via NASA

new like on March 21, 2021 at 02:01PM

NGC 1499: The California Nebula

Could Queen Calafia’s mythical island exist in space? Perhaps not, but by chance the outline of this molecular space cloud echoes the outline of the state of California, USA. Our Sun has its home within the Milky Way’s Orion Arm, only about 1,000 light-years from the California Nebula. Also known as NGC 1499, the classic emission nebula is around 100 light-years long. On the featured image, the most prominent glow of the California Nebula is the red light characteristic of hydrogen atoms recombining with long lost electrons, stripped away (ionized) by energetic starlight. The star most likely providing the energetic starlight that ionizes much of the nebular gas is the bright, hot, bluish Xi Persei just to the right of the nebula. A regular target for astrophotographers, the California Nebula can be spotted with a wide-field telescope under a dark sky toward the constellation of Perseus, not far from the Pleiades. via NASA