astrophysicist checks in: a pair of near misses : the ... - solar traffic light system

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Stars, Ashes of summer.
She often blogs for ladies. -
We hope she will be on the show later this week.
BPP from summer ash is especially recommended: Wow, it's very close to here!
Did you see it? ! ?
We didn't have one in the solar system last week, but there were two, almost none.
The asteroid TU24 buzzed over the Earth last Tuesday, while the asteroid wd4 just missed Mars on Wednesday.
Who knows so much traffic between planets? !
Little Planet Center.
While neither Earth nor Mars escaped last week's events unscathed
The earth object is a practical problem and may one day bring real danger.
According to scientists there, so far, the interior of the solar system looks like what you see on the left.
The center updates this plot daily;
It's hard not to look at it, and it's hard to realize that statistics can be bad for us in the long run.
The small planet center is operated by the Smithsonian Astrophysical Observatory under the auspices of the International Astronomical Union.
Its scientists are responsible for naming, compiling, inspecting and providing all data related to small celestial bodies in the solar system.
Including all natural satellites (moons)
Asteroid, Centauri, span
Nepenian/koiber with celestial bodies and Comet.
To see through a telescope (or even a very powerful one), the object must reflect a considerable amount of sunlight.
The rebound rate of asteroids is usually less than 5%, which means that the sunlight they reflect back is less than 5% of the impact on them, just like fresh asphalt.
That's why it's hard for them to see.
The first asteroid, Ceres, was discovered in 1801.
Astronomers have little interest in them. -
Some even call them "pests in the sky "---
Until the Observer found an asteroid close to the Earth.
The potential threat of Earth impact has attracted the attention of astronomers.
With the collision of comet Shoemaker
Levy fees on Jupiter and increasingly accept proposals that asteroid impact could lead to Cretaceous
The third extinction has turned the threat into reality.
Now everyone is looking at every new discovery. Earth object (NEO)
Bringing hype and worrying about it can be a big problem.
It may be such a day (
This is the subject of another article)
But today NASA's
The Earth target Project Office has taken control of everything.
On October, the Katalina sky survey found asteroids TU24 and wd4. 11 and Nov.
It's 2007, but it doesn't make any sense to see just one asteroid once.
In order for astronomers to correctly calculate their physical properties, such as size, mass, composition, rotation, and orbit, asteroids must be observed many times ---
The more the better.
Among them, size and orbit are the most important when potential collisions with the Earth are threatened.
Multiple observations for several consecutive nights have enabled astronomers to see how the light reflected by the asteroid changes, helping them estimate the overall shape and size of the asteroid.
Tracking its path relative to the background star can measure its distance and orbital path from the Earth.
Together, these parameters help astronomers determine whether an asteroid might pose a danger to us.
Potentially Dangerous Asteroids are on the watch list and are continuously monitored around the world.
Due to detailed tracking
Through observations of the TU24 and wd4 asteroids, we now have more knowledge of them.
Meet the asteroid TU24: within a few hours, the Goldstone Solar System Radar Telescope captured this series of images in the Mojave Desert.
While the resolution is not very high, about 20 m per pixel, the movement of the brightest points in each image clearly shows how the asteroid rotates.
These images also allow astronomers to estimate the size of asteroids to about 800 feet (250 meters)
Diameter, or about the length of a half cross
Manhattan neighborhood.
Finally, TU24 passed us at a safe distance of 0.
003 astronomical units--1.
The distance to the moon is four times the distance. -
About 334,000 miles.
The closest 12 hours ago, the Arecibo Telescope and the Green Bank Telescope were able to get the funky images on the left.
Now look at the asteroid wd4: It's kind of like a camera.
With less observation, we know less about it.
But the most important details-
It won't hit the Earth--
Thankfully confirmed.
Mars is a different story.
The Red Planet's chance of impact is 1 out of 75, which is very high when writers mainly deal with statistics close to 1 out of millions or one billion.
Still, the possibility of wd4 being completely missing from Mars is close to 99%.
The orbit of the asteroid is close to the orbit path of the Earth (
We started crossing in a long time there)
Continue to intersect Mars, as shown in the chart on the left posted by NASA in the middleDecember.
Wd4 is expected to travel with a limit of 13-and-a-
Half a kilometer per second, which makes it inevitable whether a collision with Mars is some uncertainty.