Join in expert discussion on the topics of Astronomy, astrophysics and cosmology. This may include discussion on celestial objects, space, and the physical universe as a whole. Mainstream science only.
Threads
Undergrad Milky Way; How do we know it's a spiral?
- AdkinsJr
- · Replies 10 ·
Graduate Dark Matter: Can It Stop Universe Expansion?
- LSulayman
- · Replies 4 ·
Graduate Circular restricted three body problem
- Deadstar
- · Replies 1 ·
Undergrad Is the big bang really an explosion if spacetime itself began then?
- MathematicalPhysicist
- · Replies 12 ·
High School Where Is Dark Matter in Our Universe?
- universe11
- · Replies 20 ·
Undergrad The number of space debris objects beyond the geostationary orbit
- Eagle9
- · Replies 3 ·
Undergrad History of Black Holes: Formation and Timing After the Big Bang
- PhilKravitz
- · Replies 4 ·
Undergrad Why Does t=1/H Represent the Age of the Universe?
- LSulayman
- · Replies 9 ·
Graduate Can Non-Standard Coordinates and Dimensions Explain Dark Matter?
- geordief
- · Replies 2 ·
Graduate Understanding Dark Energy and Its Impact on the Expansion of the Universe
- nekdolan
- · Replies 4 ·
Graduate What is happening in distant galaxies like Andromeda at present?
- asimations
- · Replies 29 ·
Undergrad How can we prove black holes exist if they absorb light?
- a.ratnaparkhi
- · Replies 13 ·
High School Do all stars belong to galaxies?
- Hot Star
- · Replies 6 ·
Graduate What Happens to Lost Gravitational Energy in Degenerate Matter?
- cepheid
- · Replies 2 ·
Undergrad Hanny's Voorwerp imaged by Hubble.
- turbo
- · Replies 2 ·
Graduate What Happens After a Star Fuses Hydrogen in Its Core?
- rawhemi
- · Replies 5 ·
Undergrad Why doesn't ice in Saturn's ring sublime away?
- KenJackson
- · Replies 8 ·
Undergrad Do closer galaxies appear denser when looking back to the early universe?
- binbots
- · Replies 11 ·
Undergrad Where Does the Energy Go When Gravity Changes an Asteroid's Trajectory?
- ofirgil
- · Replies 5 ·
Graduate Is There a Total Electric Charge for the Universe?
- humanino
- · Replies 16 ·
Novel-Travel inside the Black Holes
- Eagle9
- · Replies 2 ·
Graduate Evidence for orgin of CMB primary anisotropies
- zonde
- · Replies 5 ·
Bright stationary object in the sky that moves away when I approach it
- lwymarie
- · Replies 20 ·
Undergrad Could Europa's Subsurface Ocean Support Life?
- Arch Enemy
- · Replies 3 ·
High School Sun disappearing thought experiment
- texasblitzem
- · Replies 21 ·
Graduate How Do Einstein's and Modern Cosmological Constants Differ?
- LSulayman
- · Replies 2 ·
High School Are Planetary Orbits in the Solar System Flat or 3D?
- geoffleonard
- · Replies 2 ·
Graduate The present expansion of the universe
- se00064
- · Replies 9 ·
Graduate Is dark matter distribution clumpy or homogenous?
- BernieM
- · Replies 4 ·
High School How did astronomers chart star positions and planetary paths by hand?
- Opus_723
- · Replies 10 ·
Graduate Can You Answer These Four Conceptual Questions About Black Holes?
- Mileman10
- · Replies 1 ·
Is the Estimated Value of Precious Metals on Asteroid Accurate?
- aquitaine
- · Replies 7 ·
Undergrad How Do Gas Giants Retain Massive Atmospheres?
- Nakisima
- · Replies 7 ·
High School What are the factors that affect the speed of light?
- Rohan Sahuji
- · Replies 17 ·
Graduate Could Stellar Black Holes Account for Half of Dark Matter in the Universe?
- Imax
- · Replies 9 ·
Graduate I from a cosmologist big time. (questions about relic densities, etc.)
- shirosato
- · Replies 3 ·
Undergrad Would the Moon orbit faster without the Sun's gravity?
- termina
- · Replies 23 ·
Graduate Is the universe governed by simple law?.
- qsa
- · Replies 17 ·
Graduate Do all measurements need to be normalised?
- mysearch
- · Replies 3 ·
Stargazing Is the Explorer 130 or Astromaster 130EQ portable for camping trips?
- northern lass
- · Replies 8 ·
Graduate Bode's Law (Or better attributed as Titius' Rule)
- Phrak
- · Replies 14 ·
Graduate Cosmic Microwave Background Radiation: A Homogeneous and Isotropic Universe
- TrickyDicky
- · Replies 2 ·
Undergrad Does this article prove that parallel universes exist
- john88888
- · Replies 3 ·
Undergrad Proxima centauri main sequence duration
- dwaring28720
- · Replies 20 ·
Stargazing OECSYAZ2D114/F900 telescope shows nothing when looking through it
- Sarah help
- · Replies 2 ·
Undergrad Movement of different-sized crafts in space
- Jiketsu
- · Replies 7 ·
Chaotic universe where chance and probability rule
- ForMyThunder
- · Replies 1 ·
Graduate Acceleration of expansion as unknown reddening bias
- zonde
- · Replies 17 ·
Undergrad Can Wormholes and Dark Matter Lead to Time Travel?
- FantasyQueen
- · Replies 15 ·
Graduate What Is the Significance of the Frost Line in the Asteroid Belt?
- Bemis
- · Replies 2 ·
Graduate Can sterile neutrinos explain dark matter?
- marcus
- · Replies 5 ·
Undergrad How can the universe expand if it's infinite?
- LSulayman
- · Replies 2 ·
Graduate Can the expansion of the universe exceed the speed of light?
- jskirvin
- · Replies 22 ·
Graduate What is the Universe Expanding Into Beyond the Big Bang?
- venomxx
- · Replies 26 ·
Graduate 13.1 billion light years object observed.
- Ramon163
- · Replies 14 ·
Undergrad Type 1a Supernovae and Dark Energy
- chris1969
- · Replies 3 ·
Graduate Do Dark Matter Particles Cool Over Time Due to the Stretching of Space?
- DarkMatterHol
- · Replies 2 ·
Graduate Routes to formation of a black hole?
- bcrowell
- · Replies 5 ·
Undergrad Planets' and Sun's mean angular velocity
- FutureScience
- · Replies 2 ·
Undergrad How Do Scientists Estimate the Distance to Stars?
- zli034
- · Replies 3 ·
Graduate Is Dark Matter Composed of Micro-MACHOs?
- MTd2
- · Replies 24 ·
Graduate Big bang ordinary explosion, evidence for expansion of space?
- jostpuur
- · Replies 20 ·
High School Why are there two tides a day when there is only one moon?
- mack_10
- · Replies 19 ·
Undergrad Something I don't get about Wormholes
- Silverbackman
- · Replies 39 ·
Graduate Accepted (precise) value for lunar L2 point?
- Muon Cat
- · Replies 3 ·
Do moons always get more attention than the gas giant planets they orbit?
- Simfish
- · Replies 6 ·
Undergrad The time of becoming a red giant
- fawk3s
- · Replies 12 ·
Graduate Red shift of light reflected from universe boundary
- asimations
- · Replies 4 ·
Undergrad Was the primordial singularity surrounded by space and time?
- 36grit
- · Replies 23 ·
Graduate Earth-Moon vs Earth-Sun Lagrangian Point system
- cbschriks
- · Replies 2 ·
Graduate How can parallel universes be proved to exist if they are unobservable?
- khanster
- · Replies 30 ·
Stargazing How to estimate distance by a telescope
- zli034
- · Replies 4 ·
Graduate Empirical establishing of Mass-Radius relation for stars
- Pawell
- · Replies 5 ·
Graduate Could Dust Be Responsible for the Pioneer Anomaly?
- SJGooch
- · Replies 1 ·
Graduate Determination of spin-parity of Hoyle state
- ridge1988
- · Replies 1 ·
Graduate Anthropic principle and the time we find ourselves in
- carwe
- · Replies 1 ·
The Symbology of 2001, a space idiocy.
- BoulderHead
- · Replies 19 ·
High School Does particle-antiparticle annihilation explain why the universe exists?
- Darken-Sol
- · Replies 7 ·
Graduate Can a Supernova Core Reignite as a Smaller Star?
- RedAether
- · Replies 5 ·
Graduate What is the current consensus on the fate of the universe?
- Gold Barz
- · Replies 15 ·
Graduate What is space and does it form a fabric of spacetime?
- 36grit
- · Replies 37 ·
High School Why Do Stars Appear Blue to the Naked Eye but Red in Scientific Images?
- elbeasto
- · Replies 2 ·
Graduate Apparent Size of CMB Primordial Anisotropies
- fab13
- · Replies 6 ·
Graduate New red dwarf count and He-4 abundance
- TrickyDicky
- · Replies 2 ·
Graduate Is the Universe a Wave Accelerating towards a Peak?
- leonstavros
- · Replies 2 ·
Graduate Can We Ever See the Big Bang?
- imisscarl
- · Replies 1 ·
Undergrad Dark Matter: Is Gravity from a Central Mass or Cumulative Effect?
- jonnylockers
- · Replies 3 ·
Undergrad Question, Why is Mars almost sterile?
- Bearsun
- · Replies 5 ·
High School Oort cloud bodies and prevalence
- Loren Booda
- · Replies 3 ·
Undergrad Simulations - Programming languages?
- Shaybay92
- · Replies 4 ·
Graduate Does a gravitational lens have a focal point like an optical lens?
- scupydog
- · Replies 2 ·
Graduate What Explains the Helium-4 Abundance Beyond Stellar Nucleosynthesis?
- TrickyDicky
- · Replies 2 ·
Graduate How Long Does It Take for a Comet to Evaporate in the Oort Cloud?
- Reperio
- · Replies 1 ·
Undergrad Initial mass function - power law
- dntsmzns
- · Replies 1 ·
Where to find a list of galaxy masses and redshifts
- bsmith18
- · Replies 2 ·
Graduate Why Aren't Galaxies Skewed Despite Vast Distances in Light Travel?
- Astroboy
- · Replies 2 ·
Undergrad Why do astronomers stick with old languages like IDL and FORTRAN?
- Simfish
- · Replies 5 ·
Undergrad Composition of planets vs. moons
- Loren Booda
- · Replies 5 ·
Stargazing Total solar and lunar eclipses visible tonight
- Jimmy Snyder
- · Replies 25 ·
Undergrad Breaching Europas Subsurface Ocean
- jaboma
- · Replies 4 ·