What Exactly Is an Asteroid?
An asteroid is a tiny lump of solid minerals that circles the Sun and is commonly referred to as a minor planet. When the circling object is larger, it is referred to as a planetoid. They’re primarily made of the same materials as the rocky worlds of the inner Solar System, though there’s enough variance to classify them into three categories.
C-type
Carbonaceous chondrite asteroids are primarily composed of silicates and clays. The most prevalent of the three types of ancient debris clumps are fairly dark in color.
S-type
Silicates, as well as a trace of nickel-iron, are found in stony asteroids. This group contains around one-fifth of all asteroids.
M-type
Metallic asteroids are primarily composed of nickel and iron. Their bright-looking insides show varying symptoms of melting due to the Sun’s heat, depending on where they formed.
They are either the remnants of aggregated dust and rock from before our planets formed, or – in some rare situations – baby planets called planetesimals that were blasted apart before they could expand into new worlds.
The majority of what we know about asteroids comes from viewing them from afar or examining bits that fall to the Earth’s surface. All of that is changing as missions are launched to explore them up close, yielding photos and even pristine samples of asteroid material.
Classifications of Asteroids
The Primary Asteroid Belt
The vast majority of known asteroids orbit in the asteroid belt between Mars and Jupiter, with very short orbits. It is predicted that the belt contains between 1.1 and 1.9 million asteroids larger than one kilometer (0.6 miles) in diameter, as well as millions of smaller ones. Early in the solar system’s history, the gravity of newly formed Jupiter halted the creation of planetary bodies in this region, causing the small particles to crash and break into the asteroids we see today.
Trojans
These asteroids circle a larger planet but do not collide with it because they cluster at two specific spots in the orbit (called the L4 and L5 Lagrangian points). There, the Sun’s and planet’s gravitational pull balanced by a trojan’s proclivity to fly out of orbit. The Jupiter trojans are the most populous group of trojan asteroids. They consider as numerous as the asteroids in the asteroid belt. Mars and Neptune’s Trojans discover, and NASA announced the discovery of an Earth trojan in 2011.
Near-Earth Objects (NEAs)
These objects have orbits that are very close to Earth’s. Earth-crossers are asteroids that cross Earth’s orbital path.
What Gives Asteroids Their Names?
When it comes to naming asteroids, the International Astronomical Union’s Committee on Small Body Nomenclature is not particularly stringent. As a result, there a big space rock named Mr. Spock orbiting the Sun – a cat named after the “Star Trek” figure. Space rock has also named after the late rock singer Frank Zappa. There are also more solemn memorials, like the seven asteroids named after the crew of the Space Shuttle Columbia, which lost in 2003.
Asteroids also given names based on locales and several other factors. (Because the International Astronomical Union forbids naming asteroids after pets, Mr. Spock stands alone.)
Asteroids also assigned a number, such as (99942) Apophis. The Harvard Smithsonian Center for Astrophysics maintains a somewhat up-to-date list of asteroid names.
Will an asteroid strike the Earth?
On January 18, 2022, a huge stony asteroid will pass Earth safely. It expected to roughly 3,280 feet tall (about 1 km or.6 miles), which is nearly 2 1/2 times the height of the Empire State Building. As the designation (7482) 1994 PC1 indicates, this asteroid has recognized since 1994. Because of size and relatively close known flybys of our planet, it designated as a Potentially Hazardous Asteroid. Every 600,000 years, an asteroid of this magnitude crashes Earth. However, we have nothing to worry about 1994 PC1’s close approach in 2022. And, as a bonus, amateur astronomers with backyard telescopes may catch a glimpse of it when it speeds by.
Asteroid 7482 is potentially dangerous.
On August 9, 1994, Robert McNaught discovered asteroid (7482) 1994 PC1 at Australia’s Siding Spring Observatory. Astronomers discovered the space rock on older photos from other sightings dating back to September 1974, using its trajectory as a guide. It orbit well determined after 47 years of monitoring.
On January 18, 2022, at 4:51 p.m. EST, the planet will make its closest approach to Earth (21:51 UTC). This will be the closest approach for this asteroid for at least the next 200 years, according to astronomers who analyzed its orbit.
The speeding asteroid will pass 1.2 million miles (1.93 million km) from Earth, or around 5.15 times the distance between Earth and the moon. That’s a pretty safe distance, yet it’s close enough for a modest backyard telescope to see.
The massive space rock is moving at a relative speed of 43,754 miles per hour (19.56 kilometers per second) to Earth. Because of its high speed, amateur astronomers will be able to identify the speedy asteroid. Throughout the evening, it will appear as a point of light, similar to a star, passing in front of background stars. The brightness of asteroid (7482) 1994 PC1 will be approximately magnitude 10. A 10-magnitude object is a good target for observers using a 6-inch or bigger backyard telescope from a dark sky location.
How to Look at It
Skywatchers with a small telescope looking in the right direction and at the right time may be able to spot asteroid (7482) 1994 PC1. Observers in North America with backyard telescopes will have the best chance of seeing the massive asteroid hours after its close approach on January 18. (see charts below). Because of its size and proximity, you should be able to notice the motion of the space rock. The movement will be more evident when the asteroid passes close to fixed background stars.
Another effective method for spotting the asteroid is to attach a camera to the telescope and capture 30 to 45-second exposures. Point the camera and telescope at a reference star or object in the asteroid’s path. Our charts below will assist you in locating reference stars. Shorter exposures depict the asteroid as a point of light that appears in different locations in the photos, while longer exposures indicate the space rock’s motion as a streak of light.
Although the space rock (7482) 1994 PC1 would be a great target for astronomers utilizing the Goldstone Radar in California, the DSS-14 radar antenna will be unable to monitor it owing to maintenance.
On January 18, asteroid 7482’s finder maps were released.
On January 18, 2022, at about 7:25 p.m. EST, the asteroid (7482) 1994 PC1 will be located (January 19 at 00:25 UTC). Observers using a computerized or GoTo telescope can easily discover the space rock by pointing the device towards the reference star HIP 8210, which will appear as a “slowly moving star” in front of the stars. Eddie Irizarry/ Stellarium created the illustration.
At 7:45 p.m. EST on January 18, 2022 (January 19 at 00:45 UTC). At that moment, point it at the dim galaxy IC 1723 to see the massive asteroid (7482) 1994 PC1 gently moving in front of the stars. Eddie Irizarry/ Stellarium created the illustration.
Asteroid (7482) 1994 PC1 will be located on January 18, 2022, around 8:45 p.m. EST (January 19 at 01:45 UTC). The space rock will travel close to the location of star HIP 7620. Observers can point their telescopes towards the reference star and compare the results 5 minutes later to find the “slowly moving asteroid” (slow from our perspective). Eddie Irizarry/ Stellarium created the illustration.
At 9:35 p.m. EST on January 18, 2022 (January 19 at 02:35 UTC). At that time, the space rock travels through the orbit of star HIP 7184. Eddie Irizarry/ Stellarium created the illustration.
Observers can target their GoTo or computerized telescope at star HIP 7011 on January 18, 2022, at 10:00 p.m. EST (January 19, 03:00 UTC). Within 5 minutes, the space rock will pass practically directly in front of the reference star! Eddie Irizarry/ Stellarium created the illustration.
Bottom line: On January 18, 2022, a massive asteroid the size of the Golden Gate Bridge will pass Earth. The asteroid presents no threat to Earth
and will pass more than five times the distance between Earth and the moon during its closest approach.
