Space: Astronomy and Astrophysics

7,551 topics in this forum

1. First words/speech on Mars? 1 2 3

   By TioW42, December 5, 2015
   • 56 replies
   • 5.5k views
   • 
   • Derek Willis
   • March 24, 2016

2. We know NOTHING! 1 2 3

   By acute, March 26, 2016
   • 56 replies
   • 7.2k views
   • 
   • DingoLingo
   • April 8, 2016

3. Further evidence of Planet Nine discovered 1 2 3

   By UM-Bot, March 29, 2016
   • 56 replies
   • 5.4k views
   • 
   • badeskov
   • April 9, 2016

4. X10+ solar flare earth bound 1 2 3

   By preacherman76, September 6, 2017
   • 56 replies
   • 3.9k views
   • 
   • pallidin
   • September 17, 2017

5. Comoving distance- light travel distance 1 2 3

   Let's solve this mystery

   By Weitter Duckss, November 19, 2019
   • 56 replies
   • 3.3k views
   • 
   • Weitter Duckss
   • January 29, 2020

6. Space Exploration Astral Projection Style 1 2 3

   Organic Connections

   By rapture, August 14, 2014
   • 54 replies
   • 5.7k views
   • 
   • Merc14
   • September 23, 2014

7. Age of the Universe 1 2 3

   By pallidin, September 14, 2017
   • 54 replies
   • 3.9k views
   • 
   • Derek Willis
   • October 28, 2017

8. Universe expansion rate mystery deepens 1 2 3

   By UM-Bot, July 18, 2019
   • 54 replies
   • 3.4k views
   • 
   • Harte
   • August 24, 2019

9. Asteroid Safety...Are we safe? [merged] 1 2 3

   U.S. Senate Hearings on Space Threats

   By AsteroidX, March 20, 2013   

   • charles bolden
   • pray
   • (and 1 more)

     Tagged with:

     • charles bolden
     • pray
     • asteroid
   • 53 replies
   • 6k views
   • 
   • spayneuter
   • March 29, 2013

10. Observable Universe Is Likely Infinite 1 2 3

    By Xynoplas, January 21, 2014
    • 53 replies
    • 3k views
    • 
    • spacecowboy342
    • January 24, 2014

11. Earth gets new companion for trip around sun 1 2 3

    Asteroid 2014 OL339 is the latest quasi-satellite of Earth

    By Waspie_Dwarf, October 2, 2014   

    • asteroids
    • quasi-satellites
    • (and 2 more)

      Tagged with:

      • asteroids
      • quasi-satellites
      • 2014 ol339
      • earth
    • 53 replies
    • 5.3k views
    • 
    • Junior Chubb
    • October 9, 2014

12. [Merged] Closest habitable planet near Earth 1 2 3

    By Ozfactor, August 15, 2016
    • 53 replies
    • 5.7k views
    • 
    • badeskov
    • September 2, 2016

13. Mars - The current water theory 1 2 3

    Might it be wrong and need revising?

    By ocpaul20, January 3, 2020
    • 53 replies
    • 3.3k views
    • 
    • Eldorado
    • December 13, 2020

14. What if 1 2 3

    Hubble Telescope

    By Mistydawn, May 10, 2015
    • 52 replies
    • 4.4k views
    • 
    • Olate1
    • June 21, 2015

15. Report: White dwarfs is small stars 1 2 3

    White dwarfs (small stars) are not White Dwarfs

    By Weitter Duckss, August 31, 2019   

    • white dwarfs; hot stars;  rotation speed
    • 52 replies
    • 2.5k views
    • 
    • Weitter Duckss
    • December 3, 2019

16. First ever black hole image released 1 2 3

    By Still Waters, April 10, 2019   

    • black hole image
    • m87
    • 51 replies
    • 3.6k views
    • 
    • Noteverythingisaconspiracy
    • April 15, 2019

17. Is Pluto A Planet? (Merged Thread) 1 2 3

    Solar System: 8, 10 or 20 Planets?

    By Waspie_Dwarf, June 23, 2006
    • 50 replies
    • 6.5k views
    • 
    • Waspie_Dwarf
    • March 18, 2007

18. black holes 1 2 3

    By danielost, January 2, 2010
    • 50 replies
    • 4.8k views
    • 
    • danielost
    • January 4, 2010

19. Einstein Fooled You All 1 2 3

    By Montezuma III, May 25, 2019
    • 50 replies
    • 2.8k views
    • 
    • SHaYap
    • September 13, 2019

20. Evidence of ninth planet 1 2

    Astronomers say a Neptune-sized planet lurks beyond Pluto

    By bmk1245, January 20, 2016
    • 49 replies
    • 5.6k views
    • 
    • Imaginarynumber1
    • February 22, 2016

21. Could a 'bubble of nothing' eat the universe? 1 2

    By UM-Bot, March 9, 2020
    • 49 replies
    • 2.7k views
    • 
    • Waspie_Dwarf
    • March 23, 2020

22. Invisible star 'shooting comets at Earth' 1 2

    Brown dwarf could have caused mass extinctions

    By psyche101, March 12, 2010
    • 48 replies
    • 9.9k views
    • 
    • danielost
    • March 23, 2010

23. Could a Comet Hit Mars in 2014? [merged x2] 1 2

    By Waspie_Dwarf, February 26, 2013   

    • mars
    • comets
    • (and 3 more)

      Tagged with:

      • mars
      • comets
      • impact
      • comet c/2013 a1
      • comet siding spring
    • 48 replies
    • 6.1k views
    • 
    • Hazzard
    • April 15, 2013

24. time to redefine or define some terms. 1 2

    By danielost, September 27, 2013
    • 48 replies
    • 4k views
    • 
    • Lilly
    • October 5, 2013

25. how constant, in fact, are "constants"? 1 2

    can we even know for sure?

    By Rolci, December 14, 2013
    • 48 replies
    • 4k views
    • 
    • spacecowboy342
    • February 3, 2014