Before local midnight on August 12, this brilliant Perseid meteor flashed above the Poloniny Dark Sky Park, Slovakia, planet Earth. Streaking beside the summer Milky Way, its initial color is likely due to the shower meteor’s characteristically high speed. Moving at about 60 kilometers per second, Perseid meteors can excite green emission from oxygen atoms while passing through the thin atmosphere at high altitudes. Also characteristic of bright meteors, this Perseid left a lingering visible trail known as a persistent train, wafting in the upper atmosphere. Its development is followed in the inset frames, exposures separated by one minute and shown at the scale of the original image. Compared to the brief flash of the meteor, the wraith-like trail really is persistent. After an hour faint remnants of this one could still be traced, expanding to over 80 degrees on the sky. via NASA https://ift.tt/2Bkgnn6

The brief flash of a bright Perseid meteor streaks across the upper right in this composited series of exposures made early Sunday morning near the peak of the annual Perseid meteor shower. Set up about two miles from Space Launch Complex 37 at Cape Canaveral Air Force Station, the photographer also captured the four minute long trail of a Delta IV Heavy rocket carrying the Parker Solar Probe into the dark morning sky. Perseid meteors aren’t slow. The grains of dust from periodic comet Swift-Tuttle vaporize as they plow through Earth’s upper atmosphere at about 60 kilometers per second (133,000 mph). On its way to seven gravity-assist flybys of Venus over its seven year mission, the Parker Solar Probe’s closest approach to the Sun will steadily decrease, finally reaching a distance of 6.1 million kilometers (3.8 million miles). That’s about 1/8 the distance between Mercury and the Sun, and within the solar corona, the Sun’s tenuous outer atmosphere. By then it will be traveling roughly 190 kilometers per second (430,000 mph) with respect to the Sun, a record for fastest spacecraft from planet Earth. via NASA https://ift.tt/2vMpgAH

When is the best time to launch a probe to the Sun? The now historic answer — which is not a joke because this really happened this past weekend — was at night. Night, not only because NASA’s Parker Solar Probe’s (PSP) launch window to its planned orbit occurred, in part, at night, but also because most PSP instruments will operate in the shadow of its shield — in effect creating its own perpetual night near the Sun. Before then, years will pass as the PSP sheds enough orbital energy to approach the Sun, swinging past Venus seven times. Eventually, the PSP is scheduled to pass dangerously close to the Sun, within 9 solar radii, the closest ever. This close, the temperature will be 1,400 degrees Celsius on the day side of the PSP’s Sun shield — hot enough to melt many forms of glass. On the night side, though, it will be near room temperature. A major goal of the PSP’s mission to the Sun is to increase humanity’s understanding of the Sun’s explosions that impact Earth’s satellites and power grids. Pictured is the night launch of the PSP aboard the United Launch Alliances’ Delta IV Heavy rocket early Sunday morning. via NASA https://ift.tt/2wasUDP

Is there a bridge of gas connecting these two great galaxies? Quite possibly, but it is hard to be sure. M86 on the upper left is a giant elliptical galaxy near the center of the nearby Virgo Cluster of galaxies. Our Milky Way Galaxy is falling toward the Virgo Cluster, located about 50 million light years away. To the lower right of M86 is unusual spiral galaxy NGC 4438, which, together with angular neighbor NGC 4435, are known as the Eyes Galaxies (also Arp 120). Featured here is one of the deeper images yet taken of the region, indicating that red-glowing gas surrounds M86 and seemingly connects it to NGC 4438. The image spans about the size of the full moon. It is also known, however, that cirrus gas in our own Galaxy is superposed in front of the Virgo cluster, and observations of the low speed of this gas seem more consistent with this Milky Way origin hypothesis. A definitive answer may come from future research, which may also resolve how the extended blue arms of NGC 4435 were created. via NASA https://ift.tt/2KUXHts

This shock wave plows through interstellar space at over 500,000 kilometers per hour. Near the top and moving up in this sharply detailed color composite, thin, bright, braided filaments are actually long ripples in a cosmic sheet of glowing gas seen almost edge-on. Cataloged as NGC 2736, its elongated appearance suggests its popular name, the Pencil Nebula. The Pencil Nebula is about 5 light-years long and 800 light-years away, but represents only a small part of the Vela supernova remnant. The Vela remnant itself is around 100 light-years in diameter, the expanding debris cloud of a star that was seen to explode about 11,000 years ago. Initially, the shock wave was moving at millions of kilometers per hour but has slowed considerably, sweeping up surrounding interstellar material. In the featured narrow-band, wide field image, red and blue colors track the characteristic glow of ionized hydrogen and oxygen atoms, respectively. via NASA https://ift.tt/2MlG6Ql

What’s that green streak in front of the Andromeda galaxy? A meteor. While photographing the Andromeda galaxy in 2016, near the peak of the Perseid Meteor Shower, a sand-sized rock from deep space crossed right in front of our Milky Way Galaxy’s far-distant companion. The small meteor took only a fraction of a second to pass through this 10-degree field. The meteor flared several times while braking violently upon entering Earth’s atmosphere. The green color was created, at least in part, by the meteor’s gas glowing as it vaporized. Although the exposure was timed to catch a Perseids meteor, the orientation of the imaged streak seems a better match to a meteor from the Southern Delta Aquariids, a meteor shower that peaked a few weeks earlier. Not coincidentally, the Perseid Meteor Shower peaks again tonight. via NASA https://ift.tt/2M7Uaxv