Asteroid discovered with shortest orbit yet
Click for full image.
Astronomers have discovered an asteroid that circles the Sun with the shortest orbit yet found, flying mostly inside the orbit of Mercury.
The illustration to the right shows the asteroids orbit, which is also tilted 32 degrees from the plane of the solar system.
The orbit of the approximately 1-kilometer-diameter asteroid takes it as close as 20 million kilometers (12 million miles or 0.13 au), from the Sun every 113 days. Asteroid 2021 PH27, revealed in images acquired during twilight, also has the smallest mean distance (semi-major axis) of any known asteroid in our Solar System — only Mercury has a shorter period and smaller semi-major axis. The asteroid is so close to the Sun’s massive gravitational field, it experiences the largest general relativistic effects of any known Solar System object.
Relatively few asteroids have been found with orbits shorter than Earth’s, because to find them astronomers have to turn their telescopes sunward, where viewing is limited to the early evening or early morning. Few space-based telescopes in all wavelengths also don’t look this way much, because of the risk of damage from the intense sunlight.
It is thus unknown exactly how many asteroids exist with similar orbits. There may be many, with many having short eccentric orbits, similar to comets, that extend out to Earth’s orbit and thus pose a risk. Or there may be few, since such orbits so close to the Sun are likely to cause the asteroid’s break-up and destruction over time.
Knowing how many of course is important, in order to obtain a full census of those asteroids in the solar system that might hit the Earth. To get it will likely require placing a probe designed to look for them.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Click for full image.
Astronomers have discovered an asteroid that circles the Sun with the shortest orbit yet found, flying mostly inside the orbit of Mercury.
The illustration to the right shows the asteroids orbit, which is also tilted 32 degrees from the plane of the solar system.
The orbit of the approximately 1-kilometer-diameter asteroid takes it as close as 20 million kilometers (12 million miles or 0.13 au), from the Sun every 113 days. Asteroid 2021 PH27, revealed in images acquired during twilight, also has the smallest mean distance (semi-major axis) of any known asteroid in our Solar System — only Mercury has a shorter period and smaller semi-major axis. The asteroid is so close to the Sun’s massive gravitational field, it experiences the largest general relativistic effects of any known Solar System object.
Relatively few asteroids have been found with orbits shorter than Earth’s, because to find them astronomers have to turn their telescopes sunward, where viewing is limited to the early evening or early morning. Few space-based telescopes in all wavelengths also don’t look this way much, because of the risk of damage from the intense sunlight.
It is thus unknown exactly how many asteroids exist with similar orbits. There may be many, with many having short eccentric orbits, similar to comets, that extend out to Earth’s orbit and thus pose a risk. Or there may be few, since such orbits so close to the Sun are likely to cause the asteroid’s break-up and destruction over time.
Knowing how many of course is important, in order to obtain a full census of those asteroids in the solar system that might hit the Earth. To get it will likely require placing a probe designed to look for them.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I wonder if it’s a “pile of rubble”, or a large chunk of rock? perfect for an observational satellite to shadow!
The astroid protecting the satellite from the suns radiation and static interference, so it can perform its science mission, launching small probes, while searching the inner solar system for more astroids?
Every new discovery comes with it new possibilities…
Knowing how many of course is important, in order to obtain a full census of those asteroids in the solar system that might hit the Earth. To get it will likely require placing a probe designed to look for them.
The NEO Surveyor is already under development.
Call it Vulcan…a solar furnace. Eat out the back and focus a beam out the tailpipe.