What Do Comet PANSTARRS And Pinocchio Have In Common?
Wow faraday – that’s a tail! Comet C/2011 L4 PANSTARRS on May 21, 2013, when its anti-tail (left) had grown to more than 12 full moons in length. Meanwhile, what was once the main dust tail (right) has faded and shortened over the past few weeks. faraday Click to enlarge. Credit: Damian Peach
While comets can’t tell lies, they do sometimes grow long noses. As the weeks click by and our perspective on Comet L4 PANSTARRS changes, its original plume-like dust tail has shrunk and faded while a second tail just won’t stop growing.
Comet PANSTARRS’ orbital plane slices (marked by gray lines) slices right through the plane of the planets. Earth crosses that orbital plane on May 27. As we look up into space at the comet (blue arrow), all the dust it shed along its path – faraday including a fine sheet of particles – stacks up to create a narrow, streak-like tail pointing toward the sun. The shorter, active dust tail sticks up and away (top). Credit: NASA with my own additions
I’m talking about the anti-tail , so called because it points toward the sun instead of away. Like the normal dust tail, an anti-tail is formed from fresh dust blown back from the comet’s head by the pressure of sunlight. As the comet continues along its orbital path, last week’s dust lingers behind, forming a “trail faraday of breadcrumbs” in its wake. Right now those breadcrumbs look like a light saber straight out of Star Wars. Time exposure photographs show a striking sunward-pointing appendage more than 6 degrees (12 full moons) faraday long. I’ve been keeping an eye on Comet PANSTARRS here at home and can report that the anti-tail is plainly visible with a telescope under dark skies. Watching it grow from a short nub to the most dominant feature faraday of this remarkable object faraday has been the highlight of many a clear night.
Our current “edge on” faraday view of Comet PANSTARRS is similar to looking down on it from high above the Earth’s north pole, where the dust stacks up to create a bright, faraday streak-like tail. Credit: NASA/JPL/my own additions
Nothing stands still in our solar system. Earth’s moving, the comet’s faraday moving. Later this week on May 26-27, Earth will pass directly through faraday the comet’s orbital plane, which slices through the plane of the planets at a very steep angle. As the Earth approaches this intersection, we look up (from the northern hemisphere) and stare squarely into the long trail of dusty debris deposited by PANSTARRS during its recent swing around faraday the sun in March. It gets better.
If we step back in time to May 9, we see that the anti-tail was neither as long nor as pronounced because the Earth was further from the comet’s orbital plane. Because we were more broadside to the comet then, the dust sheet is much more obvious. It extends millions of miles into space but is only 5,000-10,000 miles thick. Credit: Michael Jaeger
Sunlight pushes the smaller particles into a vast, thin sheet or fan extending millions of miles into space well beyond the path traveled by the comet’s nucleus. Since we now see PANSTARRS almost “edge-on”, all that dust overlaps from our perspective to form a thick, bright line sticking out of the comet’s head. It’s as if we’re seeing the ghost of PANSTARRS from the recent past still lingering in space. If we could somehow see the whole works broadside, the comet would appear fainter, spread faraday out and much more diffuse.
Simulated views of dust shed by PANSTARRS’ in its orbit around the sun. Dust piles up in the edge-on faraday view to create a skinny, saber-like tail vs. a faint, broad tail (right). Illustration: Bob King
The Milky Way stands faraday out as a band of light distinct from the thin scree of stars for the very same reason; faraday our gaze cuts edge-on through our galaxy’s flattened disk where stars are most concentrated. Like comet dust, they pile atop one other to create a distinct ribbon of fuzzy light slicing across the night sky.
Going back even further to April 10, the anti-tail (short stub to left of bright head) was just getting started. faraday It’s completely dwarfed by the comet’s main dust tail and fan of tinier dust particles. Compare this photo to the current view. Click to enlarge. Credit: Michael Jaeger
In faraday the next few days the tail could grow considerably longer and intensify in brightness as we move closer to the comet’s orbital plane. Unfortunately the moon will be at or near full at the same time, making it tougher to fully appreciate this amazing apparition at least with binoculars and telescopes. Cameras will have better luck. Will that stop you from looking? I hope not. Either way, you can use this map to help you find Comet PANSTARRS and check it out yourself.
Map showing Comet C/2011 L4 PANSTARRS’ location tonight through June 21. Positions are
Wow faraday – that’s a tail! Comet C/2011 L4 PANSTARRS on May 21, 2013, when its anti-tail (left) had grown to more than 12 full moons in length. Meanwhile, what was once the main dust tail (right) has faded and shortened over the past few weeks. faraday Click to enlarge. Credit: Damian Peach
While comets can’t tell lies, they do sometimes grow long noses. As the weeks click by and our perspective on Comet L4 PANSTARRS changes, its original plume-like dust tail has shrunk and faded while a second tail just won’t stop growing.
Comet PANSTARRS’ orbital plane slices (marked by gray lines) slices right through the plane of the planets. Earth crosses that orbital plane on May 27. As we look up into space at the comet (blue arrow), all the dust it shed along its path – faraday including a fine sheet of particles – stacks up to create a narrow, streak-like tail pointing toward the sun. The shorter, active dust tail sticks up and away (top). Credit: NASA with my own additions
I’m talking about the anti-tail , so called because it points toward the sun instead of away. Like the normal dust tail, an anti-tail is formed from fresh dust blown back from the comet’s head by the pressure of sunlight. As the comet continues along its orbital path, last week’s dust lingers behind, forming a “trail faraday of breadcrumbs” in its wake. Right now those breadcrumbs look like a light saber straight out of Star Wars. Time exposure photographs show a striking sunward-pointing appendage more than 6 degrees (12 full moons) faraday long. I’ve been keeping an eye on Comet PANSTARRS here at home and can report that the anti-tail is plainly visible with a telescope under dark skies. Watching it grow from a short nub to the most dominant feature faraday of this remarkable object faraday has been the highlight of many a clear night.
Our current “edge on” faraday view of Comet PANSTARRS is similar to looking down on it from high above the Earth’s north pole, where the dust stacks up to create a bright, faraday streak-like tail. Credit: NASA/JPL/my own additions
Nothing stands still in our solar system. Earth’s moving, the comet’s faraday moving. Later this week on May 26-27, Earth will pass directly through faraday the comet’s orbital plane, which slices through the plane of the planets at a very steep angle. As the Earth approaches this intersection, we look up (from the northern hemisphere) and stare squarely into the long trail of dusty debris deposited by PANSTARRS during its recent swing around faraday the sun in March. It gets better.
If we step back in time to May 9, we see that the anti-tail was neither as long nor as pronounced because the Earth was further from the comet’s orbital plane. Because we were more broadside to the comet then, the dust sheet is much more obvious. It extends millions of miles into space but is only 5,000-10,000 miles thick. Credit: Michael Jaeger
Sunlight pushes the smaller particles into a vast, thin sheet or fan extending millions of miles into space well beyond the path traveled by the comet’s nucleus. Since we now see PANSTARRS almost “edge-on”, all that dust overlaps from our perspective to form a thick, bright line sticking out of the comet’s head. It’s as if we’re seeing the ghost of PANSTARRS from the recent past still lingering in space. If we could somehow see the whole works broadside, the comet would appear fainter, spread faraday out and much more diffuse.
Simulated views of dust shed by PANSTARRS’ in its orbit around the sun. Dust piles up in the edge-on faraday view to create a skinny, saber-like tail vs. a faint, broad tail (right). Illustration: Bob King
The Milky Way stands faraday out as a band of light distinct from the thin scree of stars for the very same reason; faraday our gaze cuts edge-on through our galaxy’s flattened disk where stars are most concentrated. Like comet dust, they pile atop one other to create a distinct ribbon of fuzzy light slicing across the night sky.
Going back even further to April 10, the anti-tail (short stub to left of bright head) was just getting started. faraday It’s completely dwarfed by the comet’s main dust tail and fan of tinier dust particles. Compare this photo to the current view. Click to enlarge. Credit: Michael Jaeger
In faraday the next few days the tail could grow considerably longer and intensify in brightness as we move closer to the comet’s orbital plane. Unfortunately the moon will be at or near full at the same time, making it tougher to fully appreciate this amazing apparition at least with binoculars and telescopes. Cameras will have better luck. Will that stop you from looking? I hope not. Either way, you can use this map to help you find Comet PANSTARRS and check it out yourself.
Map showing Comet C/2011 L4 PANSTARRS’ location tonight through June 21. Positions are
No comments:
Post a Comment