Greatest Hits, Odds and Ends, and Thanks!

The 2nd Midterm Exam is scheduled for this Thursday, June 5th.
Students are advised to check their grades online and report any discrepancies or questions.

The previous discussion ended with considering the potential positive aspects of asteroids, specifically their vast mineral wealth.
It's uncertain if asteroid mining will be profitable, and trillions in profit seems unlikely due to economic and engineering challenges.
Progress is being made in launch capacity and the understanding of asteroids.
Asteroid mining enterprises may provide new data on the composition and distribution of different asteroid types.

The movie posits that the comet headed for Earth contains trillions of dollars worth of precious metals.
- The idea that mining asteroids and comets for resources like water can extend humanity's reach to Mars and beyond.
Carl Sagan's vision of space exploration is mentioned.
The quest to explore and satisfy curiosity is a key element in human history.

Thinkers like Grove Karl Gilbert and Ralph Baldwin shaped our understanding of impact craters on Earth and the Moon.

Asteroids hit the ground at high speeds, causing explosive craters.
The impactor is mostly obliterated into dust and debris, not buried in the crater.
An apology to Mr. Barringer, as the mining operation won't work out.

Studying impacts of various sizes leads to understanding the distribution of objects that hit Earth.
The ~10-km sized asteroid that formed the Chicxulub crater caused widespread devastation and devastated the Earth's biosphere.

Predicting and preventing catastrophes requires discovering threatening objects early.
Charles Messier and Giuseppe Piazzi are mentioned as people of great curiosity.

In "Don't Look Up", the scientists who discover the comet are not believed by the wider community, including the US Government.
Automated, all-sky surveys, driven by the US Government and Department of Defense, have discovered most NEOs greater than 1km in diameter.
Good progress is being made on finding smaller NEOs.

The LSST project, in which UW plays a big role, will further advance asteroid detection.
Projections suggest a high likelihood of finding a potentially threatening asteroid within the next 15 years.

Asteroids are assigned a value on the Torino Scale to describe the level of threat they pose.
The 2004 discovery image of Apophis is mentioned, which was initially given a Torino scale rating of 4 but is now rated at -3.

Given enough warning, threats can be mitigated via:
- Mass drivers
- Gravity tractors
- Laser ablation
- Changing the asteroid's orbit via sunlight
These slow-push methods are often inadequate, requiring more impulsive measures.

The effectiveness of kinetic impactors has been tested by the DART mission.
Plans are in place for a full-scale kinetic impactor, the Hypervelocity Asteroid Mitigation Mission for Emergency Response (HAMMER), capable of stopping ~100m asteroids.

The device could be rigged with a nuclear weapon.
A Hypervelocity Nuclear Interceptor System could destroy or disrupt large asteroids quickly.
The use of space-based nuclear weaponry or weapons based on asteroids is concerning.
Most people are more concerned about the catastrophe of an impactor striking Earth.

In "Don't Look Up", with only 6 months of notice, the plan turns to using nuclear weapons to destroy the comet.
We are better prepared than ever to detect and mitigate potential threats.
There are still ways things could slip through, especially long-period comets.
The danger recedes daily.

In "Don't Look Up", the comet is discovered with only 6 months of advance notice.
Even if an asteroid doesn't kill you, something else will.
Time is limited, no matter what.