2023 MU2 – Here it comes. (24 Jun 2023)

 Minor Planet, Solar System  No Responses »
Jun 252023
 

Many of you will have no doubt heard of the “HOUSE SIZED ASTEROID HEADING TOWARDS EARTH !!!”.

Well, there is one that will pass by the Earth this afternoon (25 Jun 2023) at 1819 CDT. JPL estimates the size, on average, to be 5 meters in diameter (16.4 feet). My van is 20′ feet long so it must be a really small house. However, it will get no closer than 134,788 miles away. That is a about 60% the distance to the Moon. It is traveling at a speed of 10,107 mph. That speed, and its proximity to the Earth, is evident in the animation below.

 

The asteroid orbits the Sun in 490.9 days. As you can see in the orbit diagram, it spends most of its time in between Earth and Mars but crosses inside Earth’s orbit for about 2 months.

2023 MU2’s orbit.
(Graphic courtesy of the JPL Small-Body Database Browser)

At the time, from our point of view, the asteroid was traversing the constellation Scutum (The Shield). This location puts it crossing into some of the denser star clouds of the Milky Way. This is why there are so many stars in the background.

The animation is composed of forty-five cropped 120 second exposures. They were taken on the evening of the 24th.

 Posted by at 14:22

Here it comes! (2023 DZ2)

 Asteroid, Minor Planet, Solar System  No Responses »
Mar 232023
 

Asteroid 2023 DZ2 is headed towards a close approach to Earth on the afternoon of the 25th of March 2023 at 1451 CDT (1951 UTC). It will pass by at an estimated distance of 108,000 miles or just under half a lunar distance. It is estimated to be about 70 meters in diameter. A light curve shows a 6-minute rotation and about a half a magnitude range in brightness leading to the conclusion that the asteroid is not spherical.

 

This is an animation of 2023 DZ2 as it approaches the Earth. Taken on the morning of the 23rd of March, it is a set of twenty 300 second exposures.

2023 DZ2’s orbit.
(Graphic courtesy of the JPL Small-Body Database Browser)

2023 DZ2 is classified as an Apollo class asteroid. These asteroids orbits have an semi-major axis greater than that of the Earth but their perihelion is less than the Earth’s aphelion. Simply stated, these asteroid’s orbits take them closer to the Sun than the Earth and further from the Sun than the Earth. This means the asteroid’s orbit crosses the Earth’s orbit.

 Posted by at 12:36

2015 RN35 (Near-Earth asteroid) (16 Dec 2022)

 Asteroid, Minor Planet, Solar System  No Responses »
Dec 172022
 

Near-Earth asteroid 2015 RN35 flew past the Earth on the 15th of December 2022 at a distance of roughly 426,000 mi (686,000 km). The size of the asteroid is estimated to be in the of 200 to 460 feet in diameter. This is close enough and large enough to get the usual internet suspects to issue dire warnings. But as usual, those predictions were way overblown.

Due to the proximity of the event to year-end holidays some were even calling it a “Christmas Asteroid”. However, with the closest approach on the 15th and the predicted visibility ending by the 19th I would argue that “Hanukkah Asteroid” would be a better moniker.

Unfortunately, on the 15th, the PTO was configured to image main belt asteroids, not near-Earth asteroids. So, it was quite a challenge to find and image something moving as quick as the asteroid was. I fully expected to get a streak as the asteroid flew through the telescope field-of-view. However, I was not expecting this.

The image shows a sparce star field with three streaks running from top to bottom, each a different brightness due to their color. There are an additional two short streaks paralleling the others where the aircraft lights were flashing.

Aircraft formation lights [CV:1x60s]

Even though I live less than a mile from the end of a major airport’s runway, I rarely get photo-bombed by one of the aircraft. There is a lot of traffic, but I am looking at too small of a chunk of sky to have one pass through that little spot. By pointing the scope in front of the anticipated path of RN35 and taking a series of blind exposures, I was able to get a quick look at it as it passed by.

The image shows a star field with a long streak as asteroid 2015 RN35 passes from middle center to upper right.

2015 RN35 [CV:1x300s]

This image was enough to encourage me to set up a different software configuration on the next night (the 16th) and take the series of images used to make the following animation. This is a series of sixty 60 second shots. Yes, you do see a satellite pass through the FOV right at the end of the video.

The asteroid is in a 654 day orbit with its aphelion just outside of Mars’ orbit.

2015 RN35’s orbit.
(Graphic courtesy of the JPL Small-Body Database Browser)

 Posted by at 10:27

Here comes Didymos (17 Sep 2022)

 Asteroid, Minor Planet, Solar System  No Responses »
Sep 222022
 

On the 26th of September NASA’s DART mission will intentionally crash a spacecraft into a moon of the asteroid (65803) Didymos. This will be the first test of a kinetic impactor to see if energy can be used to change the orbit of an asteroid. The moon’s name is Dimorphos and it orbits its parent asteroid in 11.9 hours. If successful, the impact is expected to reduce the orbital period to 11.8 hours. This will make the moon orbit slightly closer to Didymos. The ability to add or subtract energy from a potentially hazardous asteroid or comet may be critical at some future date.

This clip is ten 300 second images. The moon Dimorphos is too small for me to see.

 Posted by at 21:16

Minerva, Goddess of Wisdom, gets in the way.

 Asteroid, Minor Planet, Occultation, Solar System  No Responses »
Nov 302019
 

Asteroid (93) Minerva, named after the Roman goddess of wisdom and strategic warfare, cast a shadow across the Earth very early on the morning of the 30th of November. As the shadow crossed the US it passed directly over the PTO. The source of the light blocked by Minerva was star UCAC4 0627:033066. The ‘telescope’ icons on the map of the shadow’s path show two other sites attempting to monitor the occultation.
 

These are two frames from the series of videos taken throughout the predicted time. The frames are 26 minutes before and 26 minutes after the event.

(93) Minerva 26 minutes before the occultation.


(93) Minerva 26 minutes after the occultation.


Once the asteroid and star are close enough, their light combines into one point. If the asteroid and the observer are exactly where they are supposed to be, the asteroid will totally block the stars light. If the asteroid is bright enough, the asteroid’s light is all that will be visible. That is what happened on the 30th. If the asteroid is not very bright the star will simply disappear. By measuring the brightness of the combined objects continuously throughout the event the diameter of the asteroid can be determined. Previous occultations of Minerva have established an estimated mean diameter of 150 kilometers (93 miles). This chart shows the brightness measured during the event. The drop in brightness, when only the asteroid’s light is visible, is obvious.
 
 Posted by at 22:05
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