The universe is vast and mostly incomprehensible, with distances between stars and galaxies that make communication and travel extremely difficult. However, there are regions like globular clusters where stars are much closer, making interstellar communication possible. These clusters are densely packed with hundreds of thousands of stars, and the distance between them is much shorter than the average distance between stars in the universe.
Astronomers have also been studying the properties of stars, including their temperature and luminosity, which are used to classify them. The Sun is a relatively average G-type main-sequence star.
In other space-related news, NASA's budget is relatively small compared to the US military's budget, and the agency has been given two unused space telescopes by the National Reconnaissance Office. These telescopes are similar to the Hubble Space Telescope but have been collecting dust for years due to the lack of funding.
The video also touches on the history of space exploration, including the search for a hypothetical planet called Vulcan, which was believed to exist between the Sun and Mercury. However, the theory of relativity later explained the anomalies in Mercury's orbit, and the search for Vulcan was abandoned.
Additionally, the video discusses the challenges astronauts face when returning to Earth after an extended stay in space, including difficulty standing and walking due to the effects of gravity.
Finally, the video mentions the eight planets in our solar system and their moons, as well as the discovery of a 300-meter-wide asteroid that orbits the Earth around a Lagrangian point, making it a "trojan" asteroid.
Here are the extracted facts:
1. Almost everything in the universe is incomprehensibly distant from us.
2. Even if interstellar communication could be established, it would take years, decades, centuries, or more for information to be transceived.
3. The universe may be crowded with isolated specks of life that are unable to overcome the physical laws of the universe to communicate.
4. Not every region of the universe is equally dispersed, with globular clusters being an example of abnormally dense spherical regions of stars.
5. Each globular cluster can contain many hundreds of thousands of stars.
6. The Milky Way is currently orbited by more than a hundred globular clusters.
7. The closest star to the Sun is over 4 light-years away, but a typical distance between stars in a globular cluster is only 1 light-year.
8. Near the center of a globular cluster, stars may only be separated by a few astronomical units (AU), which is the distance between the Earth and the Sun.
9. Intelligent beings inhabiting a planet orbiting a star inside a globular cluster may find interspecies and interstellar communication to be the norm.
10. In 1974, a radio message encoded with information about humanity and Earth was beamed towards the globular cluster known as Messier 13.
11. Messier 13 is 25,000 light-years distant, so a reply to the message would take 50,000 years to arrive.
12. As of the making of this video, only one exoplanet has been detected inside a globular cluster.
13. The current system for classifying stars is known as the Morgan-Keenan classification, which categorizes stars based on their temperature and luminosity.
14. The Hertzsprung-Russell diagram is a famous representation of this system, charting the properties of some 23,000 stars with luminosity on the vertical axis and temperature on the horizontal.
15. The Sun is a relatively average G-type main sequence star.
16. Hypergiants are the largest stars in the universe by volume, while white dwarf stars are incredibly dense but voluminously small.
17. In some 5 billion years, the Sun will first expand into a red giant before condensing back into a white dwarf.
18. Once the Sun has evolved into a white dwarf, it will begin to cool down, a process that will continue for more than a quadrillion years.
19. The US military spends more than 50% of the total discretionary spending of the federal government, while NASA spends around 1.5%.
20. In 2012, NASA was given two space telescopes by the US intelligence agency known as the National Reconnaissance Office (NRO).
21. The two telescopes were built with the intention of observing the Earth but could easily be repurposed for astronomical observations.
22. The telescopes are in the same class as the Hubble Space Telescope and are currently collecting dust.
23. One of the telescopes may be launched into orbit by 2024.
24. The Soviet Union launched a probe named Venera 14 in 1981, which successfully descended onto the Venusian surface and took photographs.
25. The probe's lens cap was ejected before taking photographs, but in one case, the lens cap landed on the ground and was photographed by a preceding identical probe.
26. The lens cap was intended to strike the ground to measure the compressibility of the soil, but instead, Soviet scientists received data on the compressibility of a lens cap.
27. If astronauts and cosmonauts aboard the International Space Station need to make an emergency evacuation, they would have to board one of the two Russian-made Soyuz capsules.
28. The Soyuz capsules have a capacity of three and are designed to descend back to Earth.
29. Crew members are trained for emergency evacuations, but one problem with returning home after an extended stay on the ISS is that the human body requires time to readjust to Earth's gravity.
30. The term "cosmonaut" is used to describe Russian space travelers, while "astronaut" is used to describe American space travelers.
31. The term "cosmonaut" translates to "universe-sailor," while "astronaut" translates to "star-sailor."
32. In the early 1960s, the US military launched some 480,000,000 tiny copper needles into orbit in an attempt to create an artificial ionosphere.
33. The needles were intended to facilitate military communications by reflecting radio signals back to Earth.
34. The project was eventually scrapped in favor of communications satellites, and the needles were abandoned under the presumption that they would burn up on re-entry within a few years.
35. However, a significant percentage of the needles remain in orbit, and some have coalesced into clumps of metal due to contact welding.
36. 39 of these clumps are currently being tracked, but more are believed to exist.
37. The eight planets of the solar system are currently orbited by 175 moons.
38. The Earth has one moon.
39. Since 2010, the Earth has had a second companion in the form of a trojan asteroid known as 2010 TK7.
40. The asteroid orbits the Earth around a region in space known as a Lagrangian point.
41. A Lagrangian point is one of five points in a two-body system where the forces exerted by the two celestial masses create a sort of gravitational and centripetal equilibrium.
42. The asteroid orbits an invisible point in space known as L4 while simultaneously orbiting the Sun.
43. The classification "trojan" stems from the fact that the asteroids around the L5 and L4 points of Jupiter are named after characters from the Trojan War of Greek mythology.
44. It's been hypothesized that when Earth was still an infant, a large planet named Theia found itself in an orbit around the L5 or L4 point, much like 2010 TK7.
45. However, due to Theia being as large as Mars, its orbit quickly destabilized, and the planet eventually impacted the Earth, which may have resulted in the formation of the Moon.