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 Do Black Holes *actually* exist?
- Zelyucha
- · Replies 43 ·
Graduate Could the LHC potentially form a black hole?
- PhysicsWanabe
- · Replies 2 ·
Undergrad Near earth Asteroids and a space elevator
- Paintjunkie
- · Replies 2 ·
Graduate Does expanding space cause cumulative redshift in light from distant supernovae?
- marcus
- · Replies 8 ·
Graduate Could the universe just be a piece of something bigger?
- marshallmeyer1
- · Replies 13 ·
Graduate Is dark energy or dark matter created to keep the Cosmological constant
- arunshanker
- · Replies 3 ·
Graduate Evidence of Dark Matter within the Solar System?
- greswd
- · Replies 30 ·
Graduate Questions about Nuclear Fusion in the Sun
- enceladus_
- · Replies 9 ·
Graduate Gravitational wave equation during cosmic inflation
- pleasehelpmeno
- · Replies 11 ·
Graduate How to calculate orbitals of celestial bodies using calculus?
- eNathan
- · Replies 1 ·
Finding a list of common names for FK5 stars
- Scott S
- · Replies 1 ·
Graduate Can We Really Understand Black Holes If Nothing Can Escape Them?
- E=mc4
- · Replies 14 ·
Stargazing Choosing a telescope between $350-450 as a beginner
- NATURE.M
- · Replies 15 ·
Graduate Is the big bang singularity really a rapid expansion of spacetime?
- Apophenia
- · Replies 11 ·
Graduate Can we expect stars to become visible only in infrared after a while?
- SpaceBear
- · Replies 3 ·
Graduate Does Matter Truly Occupy Space or is it Merely Energy in a Certain State?
- big_bounce
- · Replies 2 ·
Graduate For how long the Cosmic Microwave Background was emitted?
- SpaceBear
- · Replies 1 ·
Graduate Can Gravity Act Faster Than Light?
- arunshanker
- · Replies 2 ·
Graduate Rethinking Cosmology (Steinhardt)
- marcus
- · Replies 27 ·
High School Why are we crashing with Andromeda?
- McCartney
- · Replies 20 ·
Graduate Why does dark energy flatten the universe if negative pressure causes expansion?
- HowardTheDuck
- · Replies 12 ·
Graduate Poincaré recurrence and maximum entropy
- cryptist
- · Replies 4 ·
Graduate Why is Mars so easily visible to the naked eye?
- Solon
- · Replies 8 ·
Undergrad What Form Does Matter Take When a Star 'Explodes'?
- wawatson
- · Replies 11 ·
Undergrad See far away objects in space in real time?
- robertito
- · Replies 4 ·
Planck CMB map release on March 21st
- skydivephil
- · Replies 9 ·
Graduate Coincidence of asteroid and Russian meteor at same time.
- RGregoryClark
- · Replies 10 ·
Graduate Impact of a 4 billion light-year quasar group on cosmology
- PhysicsDad
- · Replies 7 ·
Graduate Original location of the Big Bang
- Jack Bauer
- · Replies 42 ·
Undergrad Is the Moon's Orbit Influenced by Earth's Warped Space and Tidal Friction?
- a.alexandra
- · Replies 16 ·
Graduate Crude redshift anomaly experiments to review
- codex34
- · Replies 14 ·
Graduate Why isn't the universe a black hole if it started as a singularity?
- gregtomko
- · Replies 28 ·
Undergrad Calculate the equatorial rotation velocity
- Vetmora
- · Replies 8 ·
Undergrad Kepler's 3rd law - which object in numerator?
- aphysicsmanduh
- · Replies 2 ·
Graduate Is the Expansion of the Universe Accelerating Beyond the Speed of Light?
- MostlyHarmless
- · Replies 2 ·
Undergrad Do planets wave in their orbits?
- Kev2013
- · Replies 2 ·
Graduate Would a Universe be considered part of the standard model?
- NWH
- · Replies 4 ·
Graduate Is Gravitational Energy Truly Negative in a Zero-Energy Universe?
- InvalidID
- · Replies 5 ·
Graduate Inflation, as a tool for supersymmetry breaking
- pleasehelpmeno
- · Replies 3 ·
Undergrad How to explain Edwin Hubble's discoveries to a non-scientist
- Lyrassia
- · Replies 15 ·
High School Solar system is bigger than previously thought
- PhilDSP
- · Replies 1 ·
Graduate Could You Have Spotted the TanDEM-X Satellites Near Saturn?
- PhilDSP
- · Replies 5 ·
High School Can you recommend any resources for Astronomy?
- athena810
- · Replies 4 ·
Graduate Questions on observational cosmology
- pleasehelpmeno
- · Replies 3 ·
High School Why doesn't the moon eventually drift into space?
- pheadden
- · Replies 9 ·
Graduate When could the earliest rocky planets form?
- andygee
- · Replies 10 ·
Graduate Optimal speed crossing the Earth-Moon isogravitational point
- season89
- · Replies 4 ·
Graduate What is the source of dark energy?
- DiracPool
- · Replies 6 ·
High School Can We See If A Planet Is Inhabited 1 Million Lightyears away?
- DIYMobileAudio
- · Replies 12 ·
Graduate How do Trojan Asteroids effect a planets' orbits
- Eric M. Jones
- · Replies 10 ·
Huygens Titan descent movie from University of Arizona
- Garth
- · Replies 7 ·
Graduate What is the fabric of the universe?
- petm1
- · Replies 45 ·
Graduate How does solar wind create auroras if it lacks magnetic field?
- Thunderclap
- · Replies 2 ·
Undergrad Looking for a good analogy of the shape of the expanding universe
- Andrew Bone
- · Replies 3 ·
Third Van Allen belt discovered by NASA probes
- Mordred
- · Replies 3 ·
Graduate Gravitino production in the early universe.
- pleasehelpmeno
- · Replies 1 ·
Graduate What Are the Processes for Manufacturing Elements Heavier Than Iron in Stars?
- shounakbhatta
- · Replies 14 ·
Undergrad How much would comet C/2013 A1 weigh at 50 km diameter?
- Ottlite
- · Replies 2 ·
Graduate Universe older than thought? Or big bang theory wrong?
- Vierstein
- · Replies 26 ·
High School Why are some black holes larger than others if density is infinite?
- htapps
- · Replies 2 ·
High School Comets in the Northern Hemisphere vs the Southern?
- Vorde
- · Replies 1 ·
Graduate What are e-foldings and how are they used in various fields of study?
- Mordred
- · Replies 3 ·
Time Magazine: Dark Matter May Not Exist At All
- d3mm
- · Replies 3 ·
Graduate What happens when a black hole devours another black hole?
- Chemist@
- · Replies 19 ·
Undergrad Why are MACHOs in the Halo not the disk
- Daniel_G
- · Replies 8 ·
Graduate Opinion: Double Degeneracy Model for SN Ia Progenitors
- Chronos
- · Replies 1 ·
Graduate What is the significance of the Jeans length in cloud collapse?
- AbsoluteZer0
- · Replies 2 ·
Undergrad When did nuclear fusion in the sun really start ?
- dsr52
- · Replies 8 ·
Undergrad Supernova apparent magnitude from galaxy brightness change
- Froddo
- · Replies 3 ·
Graduate Life in Vastly Different Universes
- Krunchyman
- · Replies 2 ·
High School Should I buy a 12mm eyepiece with barlow or single 6mm eyepiece?
- QuantumPion
- · Replies 1 ·
Undergrad Which Celestial Body in the Solar System Allows a Probe to Orbit Fastest?
- Numeriprimi
- · Replies 2 ·
High School What are the best eyepieces for my new Orion XT8 telescope?
- QuantumPion
- · Replies 14 ·
Undergrad Finding exoplanets in the habitable zone around white dwarfs
- skydivephil
- · Replies 16 ·
High School How close does a spacecraft get to Tethys during a mission?
- Numeriprimi
- · Replies 1 ·
High School Why doesn't light travel infinitely fast ?
- sikkemike
- · Replies 37 ·
Undergrad Did Sagan describe accelerating expansion in 1988, before its discovery?
- Baltic
- · Replies 13 ·
Graduate Probability of stars in a multiverse
- jimjohnson
- · Replies 61 ·
Graduate Is There Evidence for the Universe's Expansion and a Constant Speed of Light?
- Drmarshall
- · Replies 3 ·
High School Is Andromeda Really the Nearest Galaxy to the Milky Way?
- shounakbhatta
- · Replies 1 ·
Graduate Rotation speed of a neutron star
- shounakbhatta
- · Replies 9 ·
Undergrad Does the Universe have a Frame Rate ?
- Braders790
- · Replies 11 ·
Graduate Can We See Our Own Solar System Through Gravity's Mirror?
- Slait
- · Replies 4 ·
Stargazing Is it possible to clean a telescope mirror?
- jim hardy
- · Replies 3 ·
High School What Determines Planetary Speeds?
- fouad89
- · Replies 6 ·
Graduate Will water or lava freeze in space, or would it be a gas?
- Albertgauss
- · Replies 4 ·
Undergrad Why does air rush in from colder to hotter space and not vice versa?
- jamesb100
- · Replies 7 ·
Graduate Is there a limit to the universe's expansion?
- lmoh
- · Replies 17 ·
Graduate Could elementary particles exist before inflation?
- big_bounce
- · Replies 17 ·
Graduate Thermal velocity of particles in the solar corona
- Cerdocyon
- · Replies 2 ·
Undergrad Would Earth as a moon of Saturn get sunlight on the gas-giant-facing side?
- willstaruss22
- · Replies 7 ·
Undergrad Easy steps to groom TabCosmo output for PF post format
- marcus
- · Replies 2 ·
Graduate Higgs Boson Particle: Doom for the Universe?
- DiracPool
- · Replies 3 ·
Graduate Orbiting the Sun beyond the Hill sphere
- xpell
- · Replies 6 ·
Graduate Age versus Size of the Universe
- Johninch
- · Replies 40 ·
Graduate Inflaton after chaotic inflation
- pleasehelpmeno
- · Replies 4 ·
What Are the Largest Structures in Our Universe?
- Naty1
- · Replies 1 ·
What is this dark matter discovery about?
- DiracPool
- · Replies 7 ·
Graduate How precise can Doppler shift be measured in detecting exo-planets?
- Daaavde
- · Replies 1 ·
Graduate Did the universe begin with low or high entropy?
- Cantor
- · Replies 8 ·