Near Earth Object Program | Wikipedia audio article
Channel: wikipedia tts
Date: 2019-06-16

This is an audio version of the Wikipedia Article:
https://en.wikipedia.org/wiki/Near-Earth_object


00:03:17 1 Definitions
00:06:05 2 History of human awareness of NEOs
00:06:25 2.1 Risk
00:06:37 2.1.1 Risk scales
00:10:52 2.1.2 Magnitude of risk
00:11:01 2.1.3 Highly rated risks
00:13:44 2.2 Projects to minimize the threat
00:14:40 3 Number and classification
00:16:58 3.1 Observational biases
00:22:33 3.2 Near-Earth asteroids
00:27:07 3.2.1 Size distribution
00:28:36 3.2.2 Orbital classification
00:31:23 3.2.3 Co-orbital asteroids
00:34:26 3.3 Meteoroids
00:39:15 3.4 Near-Earth comets
00:40:06 3.5 Artificial near-Earth objects
00:41:44 4 Impacts
00:46:33 5 Close approaches
00:47:46 6 Exploratory missions
00:52:50 6.1 Missions to NEAs
00:55:20 6.2 Missions to NECs
01:00:45 7 See also
01:05:05 8 References
01:05:50 9 External links
01:10:26 Missions to NECs



Listening is a more natural way of learning, when compared to reading. Written language only began at around 3200 BC, but spoken language has existed long ago.

Learning by listening is a great way to:
- increases imagination and understanding
- improves your listening skills
- improves your own spoken accent
- learn while on the move
- reduce eye strain

Now learn the vast amount of general knowledge available on Wikipedia through audio (audio article). You could even learn subconsciously by playing the audio while you are sleeping! If you are planning to listen a lot, you could try using a bone conduction headphone, or a standard speaker instead of an earphone.

Listen on Google Assistant through Extra Audio:
https://assistant.google.com/services/invoke/uid/0000001a130b3f91
Other Wikipedia audio articles at:
https://www.youtube.com/results?search_query=wikipedia+tts
Upload your own Wikipedia articles through:
https://github.com/nodef/wikipedia-tts
Speaking Rate: 0.8251472492013532
Voice name: en-US-Wavenet-E


"I cannot teach anybody anything, I can only make them think."
- Socrates


SUMMARY
=======
A near-Earth object (NEO) is any small Solar System body whose orbit brings it to proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). If a NEO's orbit crosses the Earth's and the object is larger than 140 meters (460 ft) across, it is considered a potentially hazardous object (PHO). Most known PHOs and NEOs are asteroids, but a small fraction are comets.There are over 20,000 known near-Earth asteroids (NEAs), over a hundred short-period near-Earth comets (NECs), and a number of solar-orbiting spacecraft and meteoroids large enough to be tracked in space before striking the Earth. It is now widely accepted that collisions in the past have had a significant role in shaping the geological and biological history of the Earth. NEOs have become of increased interest since the 1980s because of greater awareness of the potential danger.  Asteroids as small as 20 m can damage the local environment and populations. Larger asteroids penetrate the atmosphere to the surface of the Earth, producing craters or tsunamis.  Asteroid impact avoidance by deflection is possible in principle, and methods of mitigation are being researched.Based on how well constrained the orbit calculations of identified NEOs are, two scales, the Torino scale and the more complex Palermo scale, rate a risk.  Some NEOs have had temporarily positive Torino or Palermo scale ratings after their discovery, but as of March 2018, more precise calculations based on longer observation arcs led to a reduction of the rating to or below 0 in all cases.Since 1998, the United States, the European Union, and other nations are scanning for NEOs in an effort called Spaceguard. The initial US Congress mandate to NASA of cataloging at least 90% of NEOs that are at least 1 kilometre (0.62 mi) in diameter, which could cause a global catastrophe, had been met by 2011.  In later years, the survey effort has been expanded to smaller objects having the potential for large-scale, though not global, damage.
NEOs have low surface gravity, and many have Earth-like orbits making them easy targets for spacecraft. As of January 2019, five near-Earth comets and five near-Earth asteroids have been visited by spacecraft.  A small sample was returned to Earth in 2010, and similar missions are in progress. Preliminary plans for commercial asteroid mining have been drafted by private companies.