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11/23/2021 – Ephemeris – NASA to launch a mission to crash into an asteroid overnight tonight

November 23, 2021 Comments off

This is Ephemeris for Tuesday, November 23rd. Today the Sun will be up for 9 hours and 17 minutes, setting at 5:07, and it will rise tomorrow at 7:51. The Moon, half-way from full to last quarter, will rise at 8:17 this evening.

As of last Sunday night, it was GO for launch of NASA’s DART Mission at 1:21 am Eastern Standard Time tomorrow morning on a Falcon 9 rocket from Vandenberg Space Force Base. DART stands for Double Asteroid Redirection Test. The DART spacecraft is to smash into a small asteroid named Dimorphos, that slowly orbits another somewhat larger asteroid, Didymos. Dimorphos orbits at only 7 inches per second, so even the smallest impact should alter the orbit noticeably. About a week before the planned collision, DART will release a small CubeSat to arrive 3 minutes after the collision to survey the crash site. In 2024 the European Space Agency will launch a satellite to survey the asteroid pair and note any long-term effects, to see if this technique for diverting asteroids is feasible.

Addendum

DART at Didymos and Dimorphos to scale

DART spacecraft with Dimorphos and Didymos. The DART spacecraft is not to scale with the asteroids. See below. CREDIT: NASA/JHUAPL

Dart and asteroids to scale

Dart and asteroids to scale with terrestrial landmarks. Credit: NASA/JHUAPL

11/19/2021 – Ephemeris – The Earth is being stalked by an asteroid

November 19, 2021 Comments off

This is Bob Moler with Ephemeris for Friday, November 19th. Today the Sun will be up for 9 hours and 25 minutes, setting at 5:10, and it will rise tomorrow at 7:46. The Moon, at full today, will rise at 5:23 this evening.

We’re being stalked by an asteroid. Its name is, and I’m not going to say it twice: Kamo`oalewa or 2016 HO3 for short. It was discovered with the Pan-STARRS telescope at Haleakala on Maui on April 27, 2016. Which explains the name. It’s Hawaiian for something that oscillates. It’ll make big circles in the evening sky for a while, then it will retreat while the Earth moves ahead of it and almost overtakes it. It will oscillate in the morning sky for a while, I mean years. Then it will head around the Earth’s orbit and go back to the evening or trailing part of the orbit and the sky and do it all over. It never seems to get closer than 5 million miles away. Some astronomers think it might be a chunk of the Moon blasted off by an asteroid impact.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). They may be different for your location.

Addendum

2016HO3 (Kamo`oalewa) orbit

Kamo`oalewa (2016 HO3) orbit around the Sun, and shows how it interacts with the Earth. Credit: NASA/JPL.

Check out all the weirdness that is Kamo’oalewa here: https://en.wikipedia.org/wiki/469219_Kamo’oalewa.

10/21/2021 – Ephemeris – Defending the planet

October 21, 2021 Comments off

This is Ephemeris for Thursday, October 21st. Today the Sun will be up for 10 hours and 41 minutes, setting at 6:47, and it will rise tomorrow at 8:07. The Moon, 1 day past full, will rise at 7:29 this evening.

This is the 4th program in 8 days here on Ephemeris about asteroids. A possible collision of an asteroid or comet has been on our collective minds since the 20-some odd pieces of Comet Shoemaker-Levy 9 hit Jupiter in July 1994. In 2016 NASA established the Planetary Defense Coordination Office to manage its ongoing planetary defense efforts. Its mission is to provide early detection of potentially hazardous objects that can come within 5 million miles of the Earth’s orbit and a size large enough to cause significant damage. Asteroid sizes would be 30 to 50 meters in diameter, that’s 90 to 150 feet in diameter or larger. It will track and issue warnings of these objects when found. It will coordinate responses to any impact threat.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT-4 hours). They may be different for your location.

Addendum

Planetary Defense Coordination Office

What the Planetary Defense Coordination Office does. Credit: NASA.

10/19/2021 – Ephemeris – Introducing the DART mission

October 19, 2021 Comments off

This is Bob Moler with Ephemeris for Tuesday, October 19th. Today the Sun will be up for 10 hours and 47 minutes, setting at 6:50, and it will rise tomorrow at 8:05. The Moon, 1 day before full, will set at 7:54 tomorrow morning.

Last Saturday morning, the Lucy mission to Jupiter’s Trojan Asteroids was launched. These asteroids are forever locked in Jupiter’s orbit and will never be a hazard to the Earth. Next month, NASA will hopefully launch a mission to a much closer asteroid Didymos, which is considered a potentially hazardous asteroid. The asteroid has a diameter of a bit less than a half mile (780 meters). It also has a satellite named Dimorphos, which has acquired the nickname Didymoon, 520 feet (160 meters) in diameter. The mission called DART for Double Asteroid Redirection Test will see how the impact of a spacecraft hitting the small Didymoon will affect its orbit around the larger asteroid.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT-4 hours). They may be different for your location.

Addendum

The DART Mission

The Double Asteroid Redirection Test (DART) mission is NASA’s contribution to the international Asteroid Impact & Deflection Assessment (AIDA) program to determine the effectiveness of a spacecraft kinetic impact of an asteroid in altering its orbit. Credit: NASA.

03/29/2021 – Ephemeris – NASA will fly spacecraft Psyche to asteroid 16 Psyche

March 29, 2021 1 comment

This is Ephemeris for Monday, March 29th. Today the Sun will be up for 12 hours and 38 minutes, setting at 8:07, and it will rise tomorrow at 7:26. The Moon, 1 day past full, will rise at 9:28 this evening.

In the summer of 2022, about 15 months from now, NASA will launch a spacecraft called Psyche on a SpaceX Falcon Heavy rocket to 16 Psyche, an asteroid. 16 Psyche is a very special asteroid. It is mostly made of iron and nickel like iron meteorites and the cores of planets like the Earth. The spacecraft will be launched to get a gravity assist from Mars and will be using an ion engine to make its way to 16 Psyche and orbit it at various altitudes to see if it really is the remnant core of a protoplanet that was destroyed by collisions with other large asteroids. It would be of great interest for the future of asteroid mining companies for the precious metals it might contain. It’s big and has an average diameter of 140 miles (225 kilometers).

<p value="<amp-fit-text layout="fixed-height" min-font-size="6" max-font-size="72" height="80">The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

An artist's concept of the Psyche spacecraft orbiting the asteroid 16 Psyche
An artist’s concept of the Psyche spacecraft orbiting the asteroid 16 Psyche. The spacecraft will be sent past Mars for a gravity assist, and also use ion thrusters to speed it on its three and a half journey to the asteroid. Credit: NASA/JPL-Caltech/Arizona State Univ./Space Systems Loral/Peter Rubin

10/29/2020 – Ephemeris – A look at Bennu the asteroid

October 29, 2020 Comments off

This is Ephemeris for Thursday, October 29th. Today the Sun will be up for 10 hours and 17 minutes, setting at 6:34, and it will rise tomorrow at 8:18. The Moon, 2 days before full, will set at 7:06 tomorrow morning.

Tonight we will have Mars appearing above the bright gibbous Moon in the evening sky. Out in space NASA’s OSIRIS-REx spacecraft is still in the vicinity of the tiny asteroid Bennu. The asteroid is about 60 percent the distance between the Earth’s and Mars’ orbits, but on the far side of the Sun from us. This is why it will take 3 years to return the sample to the Earth. Bennu is small, only 743 feet (226.5 meters) in diameter. And is a rubble pile asteroid with lots of empty voids between the rocks. The sampler instead of stopping at the surface, punched into the asteroid surface a bit. Bennu was picked because is a potential hazardous asteroid and is a particularly primitive type of asteroid.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Bennu and Earth showing distance

Inner Solar when OSIRIS REx took its sample from Bennu. Bennu’s official designation is 101955 Bennu. The number designation is the consecutive number it is given when placed on the official list of asteroids and dwarf planets when its orbit is determined. Notice that it was on the other side of the Sun. Credit NASA’s Eyes app.

The asteroid Bennu is 743 feet (226.5 meters) in diameter. It is a carbonaceous asteroid. OSIRIS-REX has already discovered water bearing clays on its surface. Credit NASA

10/27/2020 – Ephemeris – NASA’s cup runneth over with asteroid bits

October 27, 2020 Comments off

This is Ephemeris for Tuesday, October 27th. Today the Sun will be up for 10 hours and 23 minutes, setting at 6:37, and it will rise tomorrow at 8:16. The Moon, half way from first quarter to full, will set at 5:04 tomorrow morning.

One week ago the NASA’s OSIRIS Rex spacecraft unfolded its sampling arm, and folded up it solar panels so as to look like a one legged stork landing and touched a small level patch of small jagged rocks on the tiny asteroid Bennu. A nitrogen bottle was triggered to blow soil and small rocks into a cylindrical container which created quite a blizzard of small rocks. A flap on the collection device was supposed to close, keeping the collected bits in, but was propped open by a large rock, so some of the contents started to leak out. Now flight controllers must gently maneuver the collector into the return canister without losing too much of the contents. The sample canister is expected to return to Earth in 2023.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Artist depiction OSIRIS-REx TAG (Touch and Go)

Artist depiction OSIRIS-REx TAG (Touch and Go) from video. Credit NASA.

Animated GIF of the actual sample collection

Animated GIF of the actual sample collection TAG (Touch and Go). Credit NASA.

For more information go to https://www.nasa.gov/osiris-rex

 

03/09/2020 – A NASA mission to the Trojans, strange asteroids in Jupiter’s orbit

March 9, 2020 Comments off

Ephemeris for Monday, March 9th. Today the Sun will be up for 11 hours and 36 minutes, setting at 7:41, and it will rise tomorrow at 8:03. The Moon, at full today, will rise at 7:46 this evening.

Lucy is a NASA mission (https://www.nasa.gov/content/goddard/lucy-the-first-mission-to-jupiter-s-trojans) whose name is not some tortured acronym. It is named for a Beatles tune and a hominid fossil found in Africa. It will set off in October next year to study two groups of strange asteroids, Jupiter’s Trojan asteroids. These asteroids lie in two swarms in Jupiter’s orbit averaging 60 degrees ahead and 60 degrees behind Jupiter. They congregate around two gravitational points in the Jupiter-Sun system called Lagrangian points, specifically L4 ahead of Jupiter and L5 behind. The Lucy spacecraft will put itself in such an orbit that it can loop between the Earth’s orbit and each of the two Trojan swarms passing by several of the asteroids. In general the names given to the asteroids are for the characters from Homer’s Iliad.  The L4 group named or the Greeks and the L5 group named for the Trojans. I’ll be visiting this mission and that of Trojan asteroids in the future. The Earth actually has one known Trojan asteroid.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum:

trojan asteroids of Jupiter

The inner solar system with Jupiter’s Trojan asteroids. The Hilda asteroids have orbital periods of 2/3rds Jupiter’s period.  Their elliptical orbits rise from the asteroid belt (white dots) to the L3, L4 and L5 points respectively. Credit: Mdf at English Wikipedia.

Lagrange points

The 5 Lagrange points about two bodies orbiting each other. The Lagrange or Lagrangian points of gravitational equilibrium were discovered by Joseph-Louis Lagrange (1736-1813). Credit Georgia State University.

12/13/2019 – Ephemeris – Tonight is the first night that straddles the peak of the Geminid meteor shower

December 13, 2019 Comments off

Ephemeris for Friday, December 13th. Today the Sun will be up for 8 hours and 50 minutes, setting at 5:02, and it will rise tomorrow at 8:12. The Moon, 1 day past full, will rise at 6:33 this evening.

Tonight and tomorrow nights will straddle the peak of the Geminid meteor shower. It is the best meteor shower of the year and it is getting more active over the years. The Moon will interfere with all but the brightest meteors. The radiant is the point in space where the meteors seem to come from, which is near the star Castor in the constellation Gemini from which the shower gets its name. The meteors will be seen all over the sky, but they all can be traced back to the radiant. The body responsible for this meteor shower is an asteroid rather than a comet with the name 3200 Phaethon. It comes very close to the sun, So it may shed bits of itself due to heat stress. I suppose I can’t resist this: That’s how the asteroid crumbles.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

3200 Phaethon showing a tail

3200 Phaethon a rock comet showing a tail as it nears the Sun. Credit NASA/STEREO

Eastern sky for Geminids

Eastern sky for Geminids at 10 p.m. December 13, 2019. On the 14th the Moon will be the same distance from Pollux but below it. Remember that the Geminid meteors will be seen all over the sky. It might help to hide the moon behind a building so as to better see the brighter meteors. Created using Stellarium.

The orbit of 3200 Phaethon

Orbit of 3200 Phaethon with the Earth and Phaethon at 10:02 p.m. December 12, 2019. (03:02 UT Dec 13) Credit TheSkyLive.com.

Geminid Orbits

Orbits of Fireballs on the night of December 13-14 as recorded by NASA’s All Sky Cameras six years ago. The preponderance of fireballs (bright meteors) are Geminids. These are published daily on Spaceweather.com. Credit: NASA and Spaceweather.com.

Eastern sky for Geminids

Eastern sky for Geminids at 10 p.m. December 13, 2019. On the 14th the Moon will be the same distance from Pollux but below it. Remember that the Geminid meteors will be seen all over the sky. It might help to hide the moon behind a building so as to better see the brighter meteors. Created using Stellarium.

From the International Meteor Organization: Observing proposal: Geminids and Full Moon

 

11/05/2019 – Ephemeris – Is the asteroid Hygiea the smallest dwarf planet?

November 5, 2019 Comments off

Ephemeris for Election Day in some places, Tuesday, November 5th. Today the Sun will be up for 10 hours even, setting at 5:26, and it will rise tomorrow at 7:27. The Moon, 1 day past first quarter, will set at 1:12 tomorrow morning.

The asteroid Hygiea is the 4th largest asteroid in the asteroid belt between Mars and Jupiter. After much study with the European Southern Observatory’s Very Large Telescope (VLT) it appears that Hygiea is very nearly spherical. Only the largest asteroid and dwarf planet Ceres is more spherical, and it’s over twice as large. Ceres is 587 miles (945 km) in diameter. Hygiea is 267 miles (430 km) in diameter. By current definition that a body not fitting the definition of planet because it hadn’t cleared it’d orbit of other objects could have the classification of dwarf planet of it was round, or in astronomer-speak has achieved hydrostatic equilibrium. If the International Astronomical Union agrees it would be the smallest dwarf planet.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

SPHERE image of Hygiea

A new SPHERE/VLT image of Hygiea, which could be the Solar System’s smallest dwarf planet yet. As an object in the main asteroid belt, Hygiea satisfies right away three of the four requirements to be classified as a dwarf planet: it orbits around the Sun, it is not a moon and, unlike a planet, it has not cleared the neighbourhood around its orbit. The final requirement is that it have enough mass that its own gravity pulls it into a roughly spherical shape. This is what VLT observations have now revealed about Hygiea.

For more from Universe Today: https://www.universetoday.com/143897/asteroid-hygiea-is-round-enough-that-it-could-qualify-as-a-dwarf-planet-the-smallest-in-the-solar-system/.