Asteroid 2033 DZ2 will swing by earth today at 2:50 p.m. EDT, Mar 25, 2023, at a close but safe distance of about 175,000 km, half the distance to the moon.
The graphic below shows the relative location of the asteroid at close approach and the shape of its 3.17 year orbit.
As asteroids go, this is a relatively small one at around 50 meters, although a direct hit could cause considerable damage in a city-size area, similar to the Tunguska event. The Tunguska event was caused by an asteroid or comet, 50-60 m in size, which exploded in the air with a force of a 12-megaton bomb, on June 30, 1908 over a sparsely populated area in Russia; it flattened an estimated 80 million trees over an area of 2,150 sq. km.
Some vital stats on asteroid 2023 DZ2 -
Parameter |
Value |
Diameter |
~50 m |
Orbital period |
3.17 years |
Discovery |
Feb 27, 2023, La Palma observatory |
Distance from earth on close approach |
~175,000 km, half the distance to the moon |
Relative velocity at close approach |
28,000 km/h |
Current magnitude |
12-13 (should be visible overnight using binoculars or a small telescope) |
Asteroid 2023 DZ2 was discovered just a month ago. Small asteroids like these are difficult to detect until they get close enough to earth.
The asteroid will be observed by observatories, including radar based ones and by citizen scientists to better characterize its properties such as mass, size and future orbit.
What are asteroids and why should we worry about them?
Asteroids are small, airless rocky worlds leftover from the formation of our solar system about 4.6 billion years ago. Early on, the birth of Jupiter prevented any planetary bodies from forming in the gap between Mars and Jupiter, causing the small objects that were there to collide with each other and fragment into the asteroids seen today.
There are millions of asteroids; the large majority of known asteroids orbit in the asteroid belt between the orbits of Mars and Jupiter, or are co-orbital with Jupiter (the Jupiter trojans). However, other orbital families exist with significant populations, including the near-Earth asteroids.
Occasional collisions and gravitational tugs perturb the orbits of asteroids into elliptical ones, some of which cross the orbits of Earth.
As of Mar 25, 2023 and according to statistics maintained by CNEOS, 31,535 near-Earth asteroids (NEOs) have been discovered. ranging in size from 1 meter up to 32 kilometers (1036 Ganymed). 2,224 of the NEOs are classified as potentially hazardous asteroids (PHAs).
Asteroids smaller than about 25 meters generally burn up as they enter the Earth's atmosphere and cause little or no damage.
The Tunguska event was caused by a stony asteroid estimated to be 50–60 meters wide. The airburst at 6–10 km above the Earth's surface flattened an estimated 80 million trees over an area of 2,150 square km. No impact crater was found.
Every 2,000 years or so, a meteoroid the size of a football field hits Earth and causes significant damage to the impacted area.
Only once every few million years, an object large enough to threaten life on Earth comes along. Impact craters on Earth, the moon and other planetary bodies are evidence of these occurrences. According to abundant geological evidence, an asteroid roughly 10 km across hit Earth about 65 million years ago. This impact made a huge explosion and a crater about 180 km across. Debris from the explosion was thrown into the atmosphere, severely altering the climate, and leading to the extinction of roughly 3/4 of species that existed at that time, including the dinosaurs.
A reminder from the Nobel Prize committee about the most famous asteroid that collided with earth -
The following animation represents a map of the increased count of all known asteroids in the solar system between Jan. 1, 1999, and Jan. 31, 2018. Blue represents near-Earth asteroids. Orange represents main-belt asteroids between the orbits of Mars and Jupiter.
Asteroid Impact Avoidance
See diary It's Asteriod Day 2021. Let's talk and learn about Asteroids, Comets and Planetary Defense for a more detailed look at asteroids, programs to detect them and techniques to defend earth from a potential collision in the future.
Epilogue
From en.wikipedia.org/… — While the chances of a major collision are low in the near term, it is a near-certainty that one will happen eventually unless defensive measures are taken. In April 2018, the B612 Foundation reported "It's 100 percent certain we'll be hit by a devastating asteroid, but we're not 100 percent sure when." Also in 2018, physicist Stephen Hawking, in his final book, Brief Answers to the Big Questions, considered an asteroid collision to be the biggest threat to the planet.
That’s not much the average person can do for planetary defense against marauding asteroids, but it helps to be aware and knowledgeable about asteroids, comets and the science of our solar system. Let’s support our scientists and various R&D efforts in this area and let’s impress upon our lawmakers that a few billion dollars spent on planetary defense will do lot more for humanity than the trillions we spend on the military and high-tech weapon systems
Happy Saturday.
References
- ssd.jpl.nasa.gov/…
- cneos.jpl.nasa.gov/… (list of upcoming near approaches)
- Sky map — theskylive.com/...
- It's Asteriod Day 2021. Let's talk and learn about Asteroids, Comets and Planetary Defense
- Center for NEO Studies (CNEOS) — cneos.jpl.nasa.gov
- Near-Earth Object Survey and Deflection Analysis of Alternatives — Report to Congress (2007) — cneos.jpl.nasa.gov/…
- National Near-Earth Object Preparedness Strategy and Action Plan (2018) — www.nasa.gov/...
- Asteroid impact avoidance — en.wikipedia.org/...