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
Graduate Gravitational motion transitions into universal expansion over distance
- Mechanic
- · Replies 3 ·
Undergrad Understanding Motion in Space Calculations
- Scott S
- · Replies 2 ·
Graduate 3 Planets converging on Leo Constellation
- Philosophaie
- · Replies 3 ·
Graduate How Do Black Holes Influence Time and Matter in Our Universe?
- ckaiser
- · Replies 11 ·
Undergrad Solar declination / solar panel array design
- blimkie.k
- · Replies 2 ·
Stargazing Need advice on telescope for astrophotography
- cronxeh
- · Replies 9 ·
Graduate Why can't we see past the surface of last scattering?
- Jocko Homo
- · Replies 7 ·
Undergrad Do countries claim territorial rights to the space directly above them?
- AsaRand
- · Replies 8 ·
High School The universe is expanding. Into what ?
- Nick666
- · Replies 1 ·
Graduate Magnitude vs Redshift Supernova 1a
- wikiwert
- · Replies 2 ·
Graduate Does time actually speed up near a black hole's event horizon?
- iRaid
- · Replies 14 ·
High School When does the Sun sets down at 71°11'
- Borek
- · Replies 2 ·
Graduate Is the Conventional Wisdom About the Universe Wrong?
- wolram
- · Replies 31 ·
Undergrad How is it that the sun affects our tides?
- itsthemac
- · Replies 5 ·
Graduate Spiral and Disk Galaxies are controlled by single parameter. What and How?
- Saul
- · Replies 28 ·
Graduate Space expansion on smaller scales
- Galap
- · Replies 1 ·
Undergrad Can a Planet Leave Its Orbit Without External Forces?
- neurotikfisch
- · Replies 3 ·
Graduate How do comets stay suspended in the Oort cloud?
- Jim Ostrowski
- · Replies 17 ·
Graduate If the universe is expanding more rapidly now
- zewpals
- · Replies 14 ·
Comparing sizes of black holes, white dwarfs, neutron stars and the sun
- hager mahdy
- · Replies 3 ·
Graduate What Happens When a Black Hole Meets an Anti-Black Hole?
- James Leighe
- · Replies 6 ·
High School Where is the Sun's magnetic north pole now?
- Bjarne
- · Replies 6 ·
Stargazing Moon Illusion to Supersize Saturday Lunar Eclipse
- Evo
- · Replies 3 ·
Graduate Why is missing baryonic matter tightly controlled in galaxies and clusters?
- Saul
- · Replies 1 ·
Undergrad Does Einstein's Theory of Relativity Predict Dark Matter?
- RCulling
- · Replies 40 ·
Undergrad Do massive objects in space act as gyroscopes?
- zewpals
- · Replies 5 ·
High School Is the Universe Really Expanding?
- joej24
- · Replies 11 ·
Graduate What if all Dark Matter searches like CDMS II remain negative?
- ensabah6
- · Replies 48 ·
Graduate What Can We Expect for ADG in a Building Like This?
- Bjarne
- · Replies 4 ·
Stargazing Can Hubble resolve features on Pluto at 28.6 AU?
- LoveTheStars
- · Replies 3 ·
High School Why does the moon have colored rings from blue to red?
- TheIconoclast
- · Replies 4 ·
Undergrad What happens to gravity in the middle of planets and stars?
- binbots
- · Replies 5 ·
Graduate Infinity and unique don’t mix. Theory
- Alestair
- · Replies 5 ·
Graduate Could a Variable G Explain Dark Energy and Matter in Our Universe?
- peter_geek
- · Replies 1 ·
Graduate Does gravity propagate at the speed of light or instantaneously?
- Denver Dang
- · Replies 17 ·
Are There Images of Phobos or Deimos Taken from Mars' Surface?
- manofthehill@
- · Replies 19 ·
Graduate Why Did the Universe Cool Down After the Big Bang?
- yasar1967
- · Replies 22 ·
High School Do Planets Spin in the Same Direction They Orbit?
- luckis11
- · Replies 27 ·
Graduate Cosmological redshift and doppler redshift
- TrickyDicky
- · Replies 16 ·
Undergrad How fast are the projectiles from a supernova?
- Gannet
- · Replies 10 ·
Graduate You could get to the speed of light. If you could synthesise gravity
- sshort75
- · Replies 4 ·
High School What classes do I need to become an astronomer?
- Brett13
- · Replies 9 ·
Undergrad Books on Cosmology of Stellar Objects
- peteb
- · Replies 1 ·
Undergrad How much did the universe grow during inflation?
- Dav333
- · Replies 1 ·
Undergrad Why does an astronaut stay with a spacecraft accelerating through space?
- LBrandt
- · Replies 8 ·
Undergrad Composition of matter in the universe
- zewpals
- · Replies 3 ·
Graduate What are the best resources for studying Quantum Cosmology?
- MathematicalPhysicist
- · Replies 1 ·
High School Why doesn't gravity pull everything back together if the universe is expanding?
- Blade_Runner
- · Replies 1 ·
Graduate Understanding the accelerating expansion of the universe based on redshift
- Laconic99
- · Replies 3 ·
Graduate Can We Detect Extraterrestrial Radio Signals Amid Solar Interference?
- kahoon
- · Replies 5 ·
Undergrad Can two planets orbit their common barycenter while orbiting the sun?
- koopa12345
- · Replies 6 ·
Undergrad Meteorite Heating: Friction or Compression?
- CatWoman
- · Replies 2 ·
High School Is a Black Hole One-Sided or a Spherical Entity?
- fakts
- · Replies 13 ·
High School How Do Astronomers Count the Number of Stars in the Sky?
- n.karthick
- · Replies 1 ·
Graduate Can dark energy be converted to electricity?
- deanbo
- · Replies 4 ·
Graduate The first CMB peak - Flat Universe
- tonyp1001
- · Replies 7 ·
Undergrad Is the Sun’s position in the Galaxy close to its predecessor’s position?
- Gannet
- · Replies 4 ·
Undergrad 13bn+ lightyears in all directions?
- PrestonMcCall
- · Replies 22 ·
Graduate Detecting an Extra-Solar ‘Earth’
- slide_Rules
- · Replies 2 ·
Graduate Is the Universe Flat or Curved According to Planck Probe Data?
- TalonD
- · Replies 40 ·
What Do the Purple Dots and Signs Represent in the LIGO Experiment Screensaver?
- ber70
- · Replies 2 ·
Undergrad Why is maximum orbital acceleration greatest at periapsis?
- myuugen
- · Replies 1 ·
Graduate Error in CMB Interpretation? Implications?
- Saul
- · Replies 10 ·
How Will the Universe End According to New Theories?
- brother time
- · Replies 22 ·
Graduate Are There 706 Potential Exoplanets in the Latest Kepler Mission Release?
- marcus
- · Replies 2 ·
Graduate Are black holes a point of singularity?
- zewpals
- · Replies 13 ·
Graduate Time required to form a black hole
- DrZoidberg
- · Replies 6 ·
Graduate Can We See Distant Galaxies at Multiple Points in Time?
- zewpals
- · Replies 3 ·
Graduate What's the probability of a universe capable of life?
- brushman
- · Replies 15 ·
Graduate What is the medium for spacetime expansion if space itself is expanding?
- Visigoth
- · Replies 16 ·
NASA's Face in Space Program - Send Your Photo to Space!
- Topher925
- · Replies 2 ·
Graduate Was the Moon Only 16,000 km from Earth During the Hadean Eon?
- Gannet
- · Replies 11 ·
Undergrad Flat Universe? Astronomer's Lecture on Why We Aren't Special
- zewpals
- · Replies 1 ·
Graduate What Is Gravitational Time Dilation and How Does It Work?
- brother time
- · Replies 2 ·
Undergrad Why is the ideal gas law a good approximation for stars?
- jimmy_jollop
- · Replies 9 ·
Undergrad Where did the moon get its orbiting energy?
- Red_CCF
- · Replies 4 ·
Graduate Matter/antimatter, mass questions
- Dav333
- · Replies 7 ·
Graduate Can Dark Energy be a Fifth Force?
- IceMan815
- · Replies 2 ·
Undergrad Cosmic Background Radiation - why is it still here?
- BernieM
- · Replies 9 ·
Graduate Star's Spin: Clockwise or Counterclockwise in Black Holes?
- JMAustin
- · Replies 1 ·
Undergrad What Happens After the Big Crunch?
- john88888
- · Replies 6 ·
Undergrad Searching for an Official Database of Solar System Properties
- Gannet
- · Replies 6 ·
Graduate Can Light Behave Differently in Moving Inertial Reference Frames?
- ABHoT
- · Replies 9 ·
Undergrad What is the Semi-Major Axis of Saturn's 10-Year Orbit?
- kami12
- · Replies 4 ·
Graduate Is spacetime globally curved with constant curvature in GR?
- TrickyDicky
- · Replies 16 ·
Undergrad Space expansion in our perspective?
- powerplayer
- · Replies 40 ·
Graduate Anomalous Quasar Observations 200k Light Year Jet? And So On.
- Saul
- · Replies 11 ·
Undergrad Understanding Phase Space and Building It
- penguin007
- · Replies 5 ·
Graduate Complete photonic view like the CMBR version
- Simon43254
- · Replies 7 ·
What information will you send to aliens?
- J.Asher
- · Replies 7 ·
Why use IRAF for image processing
- harvellt
- · Replies 5 ·
Graduate Can gamma-ray burst light curves be predicted mathematically?
- Visigoth
- · Replies 1 ·
High School Does the Tidal Effect Cause Planets to Move Away from the Sun?
- Bjarne
- · Replies 3 ·
Undergrad Longest day of year in the tropics
- bigislander72
- · Replies 12 ·
Undergrad Will Betelgeuse Go Supernova Soon?
- magnetar
- · Replies 10 ·
Undergrad 'Close Encounters' and Galaxy formation
- tomeatworld
- · Replies 5 ·
Graduate What is meant by a particle should not overclose the univese? what is overclose?
- melezmelez
- · Replies 1 ·
Undergrad How is the 3-d space an approximation of Euclidean Geometry?
- ask_LXXXVI
- · Replies 6 ·
Undergrad What Are the Chances of Life on Jupiter's Moons and Other Saturnian Moons?
- brother time
- · Replies 2 ·
Graduate Was Gravity turned off during inflation?
- rwmp
- · Replies 4 ·