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
High School Why doesn't Earth's gravity perturb Mars's orbit?
- Coda
- · Replies 6 ·
NASA Technical Report 19770013810 on infrasound effects
- Ivan Seeking
- · Replies 10 ·
Graduate Accessing raw data from cosmology experiments
- barnflakes
- · Replies 9 ·
Graduate Stable orbit velocity around a Kerr black hole
- stevebd1
- · Replies 4 ·
Undergrad Why isn't the night sky bright white from all the starlight?
- gothamxi
- · Replies 4 ·
Stargazing Why is telescope magnification M = f_o / f_e?
- quietrain
- · Replies 3 ·
Undergrad Pale blue dot: what causes the bands?
- dotancohen
- · Replies 5 ·
Undergrad A non-technical explanation for FTL quasar motions
- twofish-quant
- · Replies 3 ·
Undergrad Regardless of an expanding universe
- Yessem101
- · Replies 5 ·
Graduate A method to predict visibility of the international space station
- Esran
- · Replies 10 ·
Graduate How Does Gravity Propagate Backwards in Time?
- skeptic2
- · Replies 8 ·
Graduate Is it possible for a single super-massive black hole
- Pattonias
- · Replies 6 ·
Graduate Answering Dumb Questions about Universe Expansion and Gravity
- Saint Brian
- · Replies 24 ·
High School Why is the moon moving away from Earth?
- xMonty
- · Replies 12 ·
High School Why is the sky blue?
- kambez
- · Replies 3 ·
High School Reasons why LCROSS is a safe mission
- MajorHarrison
- · Replies 18 ·
Graduate Restructuring of the solar system theory
- Mcgilvrey007
- · Replies 10 ·
Graduate What happens to an infinite grid of hydrogen atoms over time?
- heusdens
- · Replies 30 ·
High School Where do heavy elements go after supernovae and how is hydrogen replenished?
- memphisp
- · Replies 9 ·
Graduate How to much mass does it take to change Neptune's Orbit?
- masterpiece5
- · Replies 1 ·
Graduate Nuetron star collapses to B.H., a final plunge of matter and energy?
- Spinnor
- · Replies 12 ·
Graduate Why do meteor showers recur at the same time each year?
- 7barry7allen7
- · Replies 3 ·
Graduate Is dark energy a repulsive force that causes cosmic acceleration?
- Pattonias
- · Replies 1 ·
Graduate How Do Observers Measure the Universe's Age and Size in Cosmology?
- MaxwellsDemon
- · Replies 2 ·
Graduate Could Everything Be Contracting to a Point Instead of Accelerating Away?
- quietrain
- · Replies 8 ·
Undergrad Calculation of orbital speed for given eccentricity
- theskipirate
- · Replies 2 ·
Graduate Is the Universe Analog or Digital?
- HeyCharley
- · Replies 5 ·
Undergrad How can artificial gravity be created on space stations using rotating rings?
- DWhite
- · Replies 4 ·
Are the Perseids meteor shower the best in recent years?
- flatmaster
- · Replies 7 ·
Graduate Is the CMB dipole influenced by the recession velocity of the CMB?
- Vast
- · Replies 9 ·
High School Supernova's Gamma Rays and Comets
- crays
- · Replies 6 ·
High School Difference between Supernova vs. Nova?
- pixel01
- · Replies 8 ·
Graduate What are the effects of falling matter on a black hole and its event horizon?
- Skolon
- · Replies 4 ·
Graduate Can We Truly Define the Largest and Smallest Structures in the Universe?
- Pjpic
- · Replies 4 ·
Undergrad Is Star Formation Just a Matter of Lag Time?
- thomasxc
- · Replies 3 ·
Major weightlessness discoveries and their future applications
- RJW
- · Replies 2 ·
Graduate Could the Big Bang Be the Middle of the Universe?
- gruff
- · Replies 52 ·
Graduate A theory and questions about physics/astro and quantum.
- wolfwing
- · Replies 8 ·
Undergrad Mass-dominated vs. radiation-dominated.
- borvis
- · Replies 5 ·
Graduate How to measure the CDM power spectrum?
- MykDee
- · Replies 6 ·
Graduate Inverse relationship - neutron flux density with sunspot cycle
- lemonstar
- · Replies 3 ·
Graduate Is the Universe the Size of a Grapefruit?
- antd
- · Replies 38 ·
Undergrad How is the universe's age of 13.8 billion years calculated?
- land_of_ice
- · Replies 2 ·
Graduate What is most influential candidate quantum cosmology today?
- ensabah6
- · Replies 1 ·
High School How Big is the Universe and How Did it Begin?
- land_of_ice
- · Replies 1 ·
High School How was Earth formed?
- crays
- · Replies 8 ·
High School Why Can't Space Ships Use Propellers or Jets for Manoeuvrability?
- jsea-7
- · Replies 7 ·
Undergrad Carl Zeiss Tessar 2.0/3.7 lens specifications and field of view
- FocusedWolf
- · Replies 13 ·
Undergrad Why do planets orbit in the same direction as their star's rotation?
- _DJ_british_?
- · Replies 3 ·
Graduate Last Digit of Pi in the measurable universe
- Burin
- · Replies 9 ·
Undergrad Why Do Revolving Bodies Have Elliptical Orbits?
- Shahin.Omar
- · Replies 6 ·
Graduate Inflation theory; dead or alive?
- Peter Watkins
- · Replies 13 ·
Graduate Are Black Holes Unfalsifiable and Therefore Not Science?
- AdkinsJr
- · Replies 73 ·
Graduate Absence of dust on moon and material sciences
- zankaon
- · Replies 5 ·
Undergrad What quantities does the gravitational constant relate?
- TurtleMeister
- · Replies 28 ·
Undergrad Current density of space in atoms per cubic meter
- 1123581321
- · Replies 29 ·
High School Earth's Movement and Atmosphere with a Black Hole Sun
- havaliza
- · Replies 6 ·
Graduate What is Plasma Cosmology and its impact on current scientific understanding?
- mangaroosh
- · Replies 5 ·
Undergrad Textbook on Mathematical Astronomy
- Philosophaie
- · Replies 2 ·
Undergrad Elliptical orbits and focal points
- Agent M27
- · Replies 2 ·
Graduate Black hole in one universe to generate a big bang
- baxtus
- · Replies 7 ·
Graduate Can Gravitational Lensing Cause a Star to Appear Twice Simultaneously?
- Nickelodeon
- · Replies 6 ·
High School Mercury not travelling in a straight line?
- seb7
- · Replies 1 ·
What do u recoment for somwhone thats intrested in astronomy?
- eddieberto
- · Replies 1 ·
Graduate The Small Particle That Started The Big Bang
- Ryuk1990
- · Replies 45 ·
High School Galactic Suite and space tourism
- ehilge
- · Replies 1 ·
Undergrad How do you find orbital elements from position and velocity vectors?
- Cghnasa
- · Replies 1 ·
Graduate Jets from Black Holes - do they carry momentum?
- Dmitry67
- · Replies 5 ·
Undergrad What Is the Gravity Value on Neutron Stars?
- delplace
- · Replies 2 ·
Undergrad Collisions between galaxies, geometry of expansion.
- AdkinsJr
- · Replies 2 ·
Stargazing Beginner telescope recommendations under $200
- Alexstre
- · Replies 6 ·
High School Southwest Sky Constellations: Most Recognized Patterns
- ICHO
- · Replies 3 ·
Graduate What Happens to a Stationary Bowling Ball in an Expanding Universe?
- DARKSYDE
- · Replies 4 ·
Graduate Why is 10^-36 seconds considered the starting point of inflation?
- zeebo17
- · Replies 3 ·
Graduate Mapping Underground Caves/Tunnels on the Moon/Mars
- sanman
- · Replies 2 ·
Graduate What is the universe expanding into?
- ojsimon
- · Replies 3 ·
Undergrad Finding the correct name for solar spectroscopy technique
- piareround
- · Replies 1 ·
Undergrad Why is the universe 76 billion light years across if it's only 13.7 billion years old?
- darkred
- · Replies 7 ·
High School Recommend some papers or books on Inflation
- micomaco86572
- · Replies 5 ·
Graduate Trying to comprehend the explosive power of a gamma ray burst?
- The_Absolute
- · Replies 1 ·
High School Why Do We Experience Night in Our Universe?
- loup
- · Replies 38 ·
Graduate Does the expansion of the universe also cause an increase in overall entropy?
- Entropee
- · Replies 39 ·
High School Space.com says intergalactic hydrogen gas absorbs all optical light
- thenewmans
- · Replies 7 ·
Undergrad Chance of Planet Formation without Stars
- discord73
- · Replies 19 ·
Graduate Is the Universe Expanding Slower Now Than in the Past?
- discord73
- · Replies 9 ·
Undergrad Why most of the planetary orbits are ellipitical?
- hongkongrubbish
- · Replies 18 ·
High School Why is earth's path is elliptical?
- kamalee
- · Replies 8 ·
High School So, what are all the known paradoxs in Astronomy?
- discord73
- · Replies 4 ·
Undergrad Dark matter and supermassive black holes
- Lsos
- · Replies 7 ·
Undergrad Cmb 13.7 billion light years away
- xMonty
- · Replies 17 ·
Graduate What is the more puzzling our universe with inflation or without it?
- emanaly
- · Replies 22 ·
Undergrad A hypothetical space elevator question.
- Pattonias
- · Replies 6 ·
Graduate Main sequence lifetime problem
- kranav
- · Replies 3 ·
My dwarf is bigger than your dwarf
- Loren Booda
- · Replies 9 ·
Graduate Planet's Julian Date of a point in orbit
- Philosophaie
- · Replies 1 ·
Undergrad Planets <-> solar systems <-> galaxies
- Loren Booda
- · Replies 10 ·
Comet C/2008 O2 McNaught photos?
- alseth
- · Replies 1 ·
Graduate Mass-luminosity relation problem
- kranav
- · Replies 19 ·
Undergrad What equations are needed for calculating Keplerian orbital mechanics?
- Philosophaie
- · Replies 7 ·
Graduate Using Technology to stop the expansion of space.
- pulsexx
- · Replies 2 ·