It showed up as a brief sub-second flash in videos, but a few eagle-eyes noticed the flash. From there, it was a race to confirm whether the flash originated on the moon or from some more mundane source on Earth. The flash was verified in multiple videos captured in different cities and continents, thereby confirming what may be the first widely recorded sighting of a meteor strike on the moon during a lunar eclipse event.
The flash is shown in the image below at the 7 O’Clock position, based on the video from Griffith Observatory.
MIDAS
The Moon Impacts Detection and Analysis System (MIDAS) project uses telescopes in multiple observatories located in Spain (Sevilla, La Hita and La Sagra) to observe the dark side night-time areas of the Moon and uses software to detect and analyze meteor impacts. Monitoring is done when the moon is at least half dark; monitoring is enabled during eclipse’s too, but this is the first time an impact was detected during an eclipse.
Monitoring meteor strikes on the moon provides much more accurate results of the size and frequency of these events than monitoring atmospheric strikes on Earth. The results can be extrapolated to derive similar parameters for Earth.
MIDAS locations (left). Telescope at La Hita Astronomical Observatory (16" Schmidt-Newtonian telescope, High sensitivity video camera Watec 902H Ultimate). www.cosmos.esa.int/...
NASA Lunar Impact Monitoring Program
NASA has a similar program for monitoring lunar meteoroid impacts.
Observations are conducted at the NASA Marshall Space Flight Center in Huntsville, Alabama at the Automated Lunar and Meteor Observatory (ALaMO). Uses two 14” telescopes and low light level Watec Ultimate H2 video cameras, which record continuously at 30 frames per second.
It is not clear whether this program was operating normally this week, since NASA is effectively closed down due to the federal government shutdown.
See www.nasa.gov/… for details.
Asteroids
Our solar system is a dangerous place with asteroids and comets zipping past the Earth on a daily basis. While there are no known extinction-level cosmic rocks heading towards a collision with Earth, history shows that it is a matter of time before one gets close enough to do serious damage, much more so than marauding Aliens.
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.
In the main asteroid belt, there are over 200 asteroids larger than 100 km, and between 700,000 and 1.7 million asteroids with a diameter of 1 km or more. The total mass of the asteroid belt is estimated to be about 4% of the mass of the Moon. The four largest objects, Ceres, 4 Vesta, 2 Pallas, and 10 Hygiea, account for half of the belt's total mass.
Occasional collisions and gravitational tugs perturb the orbits of asteroids into elliptical ones, some of which cross the orbits of Earth.
As of Jan 8, 2019, 19,470 near-Earth asteroids are known, ranging in size from 1 meter up to 32 km (1036 Ganymed).
Asteroids smaller than about 25 meters generally burn up as they enter the Earth's atmosphere and cause little or no damage
Every 2,000 years or so, a meteoroid the size of a football field hits Earth and causes significant damage to the area.
Only once every few million years, an object large enough to threaten Earth's civilization 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.
NASA Asteroid Grand Challenge
The NASA Asteroid Grand Challenge is a large-scale effort to detect, track, characterize, and create mitigation strategies for potentially hazardous asteroids.
In the United States, NASA has a congressional mandate to catalog all Near Earth Objects (NEOs) that are at least 1 km wide, as the impact of such an object would be catastrophic.
NASA's Near-Earth Object (NEO) Search Program
Since NASA's initiation of the NEO Observations program in 1998, Near-Earth Object (NEO) surveys have been extremely successful finding more than 90% of the Near-Earth Asteroids (NEAs) larger than one km and a good fraction of the NEOs larger than 140 meters. As of Jan 22 2018, 897 NEAs larger than 1 km have been discovered, of which 157 are potentially hazardous. The inventory is much less complete for smaller objects, which still have potential for large scale damage. 8493 objects 140 m and larger and a total of 19,489 objects all sizes have been discovered.
The vast majority of NEO discoveries have been made by NASA-supported ground-based telescopic surveys. Note that the NEO survey includes comets.
| NEO SURVEY PROGRAM |
LOCATION |
STATUS |
| LINEAR (LINCOLN NEAR-EARTH ASTEROID RESEARCH) |
Socorro New Mexico |
|
| PAN-STARRS (PANORAMIC SURVEY TELESCOPE AND RAPID RESPONSE SYSTEM) |
Haleakala, Maui, Hawaii |
|
| CATALINA SKY SURVEY (CSS) |
Tucson Arizona |
|
| SPACEWATCH |
Tucson Arizona |
Follow-up missions only |
| LONEOS |
Flagstaff Arizona |
Discontinued |
| NEAT |
NASA/JPL |
Discontinued |
| NEOWISE |
Earth polar orbit |
|
PAN-STARRS and NEOWISE
Asteroid Impact Avoidance
Here is a quick summary of various deflection techniques being explored by NASA and other space agencies (from neo.jpl.nasa.gov/...). PHO stands for Potentially Hazardous Object.
|
Impulsive Technique
|
Description
|
|
Conventional Explosive (surface)
|
Detonate on impact
|
|
Conventional Explosive (subsurface)
|
Drive explosive device into PHO, detonate
|
|
Nuclear Explosive (standoff)
|
Detonate on flyby via proximity fuse
|
|
Nuclear Explosive (surface)
|
Impact, detonate via contact fuse
|
|
Nuclear Explosive (delayed)
|
Land on surface, detonate at optimal time
|
|
Nuclear Explosive (subsurface)
|
Drive explosive device into PHO, detonate
|
|
Kinetic Impact
|
High velocity impact
|
|
Slow Push Technique
|
Description
|
|
Focused Solar
|
Use large mirror to focus solar energy on a spot, heat surface, “boil off” material
|
|
Pulsed Laser
|
Rendezvous, position spacecraft near PHO and focus laser on surface, material “boiled off” surface provides small force
|
|
Mass Driver
|
Rendezvous, land, attach, mine material and eject material from PHO at high velocity
|
|
Gravity Tractor
|
Rendezvous with PHO and fly in close proximity for extended period, gravitational attraction provides small force
|
|
Asteroid Tug
|
Rendezvous with PHO, attach to PHO, push
|
|
Enhanced Yarkovsky Effect
|
Change albedo of a rotating PHO; radiation from sun-heated material will provide small force as body rotates
|
More info on past and future missions to deflect asteroids can be found in this earlier diary “Asteroids and Planetary Defense” at www.dailykos.com/…
The NASA DART mission seems to be on track for an October 2022 head-to-head meeting with binary near-Earth asteroid (65803) Didymos. Didymos is not a threat to Earth, hence it is a good candidate to experiment on.
Asteroid Hit Rate
