100 Facts About Space

100 fascinating facts about space, covering everything from planets, stars, galaxies, black holes, and beyond:

🌌 General Facts About Space (1–20)

1. Space begins at the Kármán line, about 100 km above Earth’s surface.
2. Space is completely silent—there’s no air to carry sound.
3. The universe is 13.8 billion years old, according to current estimates.
4. Light from the Sun takes 8 minutes and 20 seconds to reach Earth.
5. One day on Venus is longer than its year.
6. Outer space is not completely empty—it contains particles, dust, and cosmic rays.
7. Neutron stars are so dense that a sugar-cube-sized amount would weigh a billion tons.
8. There are more stars in the universe than grains of sand on all Earth’s beaches.
9. Saturn is the least dense planet—it would float in water.
10. The observable universe is about 93 billion light-years across.
11. A light-year is the distance light travels in one year: about 9.46 trillion kilometers.
12. The temperature in space is about -270°C (just above absolute zero).
13. Space smells like burnt metal or welding fumes, according to astronauts.
14. The Moon moves 3.8 cm away from Earth each year.
15. Time slows down near strong gravitational fields (gravitational time dilation).
16. There are more than 100 billion galaxies in the observable universe.
17. Galaxy collisions happen, including the future collision between Milky Way and Andromeda.
18. The universe is expanding, and the expansion is accelerating.
19. The Hubble Space Telescope has been in orbit since 1990.
20. Space is full of cosmic microwave background radiation, the afterglow of the Big Bang.

🪐 Planets & Moons (21–40)

21. Jupiter is the largest planet in our solar system.
22. Mercury is the smallest and closest to the Sun.
23. Venus has the hottest surface temperature of any planet due to its thick CO₂ atmosphere.
24. Earth is the only planet known to support life.
25. Mars is home to the tallest volcano: Olympus Mons, 3 times taller than Everest.
26. Jupiter has a Great Red Spot, a storm larger than Earth.
27. Saturn’s rings are made mostly of ice and rock.
28. Uranus rotates on its side, likely due to a massive collision.
29. Neptune has the strongest winds in the solar system, up to 2,100 km/h.
30. Pluto was reclassified as a dwarf planet in 2006.
31. The largest moon in the solar system is Ganymede (Jupiter’s moon).
32. Titan, Saturn’s moon, has liquid methane lakes and a dense atmosphere.
33. Europa, another moon of Jupiter, may have a subsurface ocean.
34. Earth’s Moon is about 1/6th Earth’s gravity.
35. Mercury has no atmosphere, leading to extreme temperature swings.
36. Venus rotates clockwise (retrograde), unlike most planets.
37. Mars appears red due to iron oxide (rust) on its surface.
38. Uranus and Neptune are called ice giants.
39. Jupiter has at least 95 moons (and counting).
40. A day on Jupiter lasts only about 10 hours.

☄️ Comets, Asteroids, and Meteors (41–55)

41. Comets are icy bodies that develop tails when near the Sun.
42. The tail of a comet always points away from the Sun.
43. Halley’s Comet appears about every 76 years.
44. Asteroids are rocky bodies mostly found in the asteroid belt between Mars and Jupiter.
45. Ceres is the largest asteroid and also a dwarf planet.
46. Meteoroids are space rocks; meteors burn in Earth’s atmosphere; meteorites hit Earth.
47. The Chicxulub asteroid impact caused the extinction of the dinosaurs.
48. Oumuamua was the first observed interstellar object in our solar system.
49. Some asteroids have their own moons.
50. The Kuiper Belt is a region of icy bodies beyond Neptune.
51. The Oort Cloud is a hypothetical shell of icy objects far beyond Pluto.
52. Comet Shoemaker–Levy 9 crashed into Jupiter in 1994.
53. NASA’s OSIRIS-REx brought back samples from asteroid Bennu.
54. DART Mission successfully changed the orbit of an asteroid in 2022.
55. Asteroids could become future mining sites for rare elements.

🌠 Stars & Galaxies (56–75)

56. Our Sun is a yellow dwarf star.
57. Stars are born in nebulae, giant clouds of gas and dust.
58. The closest star system to us is Alpha Centauri, about 4.37 light-years away.
59. The largest known star is UY Scuti.
60. A supernova is the explosive death of a massive star.
61. A neutron star can spin hundreds of times per second.
62. A pulsar is a rapidly spinning neutron star that emits beams of light.
63. Black holes are formed from collapsed massive stars.
64. Sagittarius A* is the supermassive black hole at the center of the Milky Way.
65. Quasars are the brightest known objects in the universe.
66. The Milky Way is a barred spiral galaxy.
67. The Andromeda Galaxy is our nearest major galactic neighbor.
68. Galaxies can contain billions or even trillions of stars.
69. The Sombrero Galaxy is known for its distinct shape.
70. Globular clusters are dense groups of old stars.
71. A white dwarf is the leftover core of a small star.
72. Our Sun will become a white dwarf in about 5 billion years.
73. Betelgeuse, a red supergiant, is expected to explode as a supernova one day.
74. The light from some stars takes millions of years to reach us.
75. Interstellar space begins where the solar wind stops, beyond the heliopause.

🧠 Mind-Blowing & Fun Facts (76–100)

76. If you fell into a black hole, you’d be spaghettified by gravity.
77. A teaspoon of neutron star material would weigh billions of tons.
78. The ISS (International Space Station) travels at 28,000 km/h.
79. Astronauts grow 2 inches taller in space due to spinal decompression.
80. Space has no atmospheric pressure—your blood would boil without a suit.
81. You can’t burp in space—gas and liquid don’t separate in zero gravity.
82. Earth orbits the Sun at 107,000 km/h.
83. The Sun makes up 99.86% of the mass in the solar system.
84. A day on the Moon lasts about 29 Earth days.
85. Venus has no moons.
86. Mars has two moons: Phobos and Deimos.
87. Black holes don’t “suck”—they pull objects only within their event horizon.
88. Gravitational waves were first detected in 2015 by LIGO.
89. The universe may be infinite, but the observable part is finite.
90. The Voyager 1 spacecraft is the farthest human-made object from Earth.
91. There is a “cold spot” in the cosmic microwave background that puzzles scientists.
92. Some exoplanets rain glass or iron due to extreme atmospheres.
93. There’s a planet made of crystalline carbon (diamond)—named 55 Cancri e.
94. Water has been found on the Moon, Mars, and some asteroids.
95. Space junk is a growing concern in low Earth orbit.
96. Mars sunsets appear blue due to fine dust particles.
97. Space tourism is now real—companies like SpaceX and Blue Origin have sent civilians.
98. The James Webb Space Telescope (JWST) launched in 2021 offers deeper cosmic views than ever before.
99. The Big Bang wasn’t an explosion in space—it was an expansion of space itself.
100. Scientists estimate there may be over 6 billion Earth-like planets in our galaxy alone.