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 Why don't all neutron stars collapse into black holes?
- dect117
- · Replies 23 ·
Graduate Distinction between special and general relativity
- bcrowell
- · Replies 51 ·
High School Why does the sun appear closer at the beach horizon than from a balcony?
- avito009
- · Replies 1 ·
Graduate Re Dark Matter and the Horizon Problem
- Buzz Bloom
- · Replies 3 ·
Graduate What Causes the Higher Peaks and Damping Tail in the CMB Power Spectrum?
- gluon
- · Replies 4 ·
Undergrad How Would a Halved Earth Mass Affect the Moon's Rotation Period?
- nmsurobert
- · Replies 2 ·
Graduate Is the location of galaxy X in the universe constant?
- HZY
- · Replies 22 ·
Lunar super eclipse Sept. 27th. 2015
- hagar
- · Replies 49 ·
High School Find 1.25" Focuser for 8" Newtonian Telescope
- zeriodpeezeriod
- · Replies 2 ·
Graduate Negative energy is repulsive, but PE is negative, so?
- nomadreid
- · Replies 2 ·
High School Need reliable resources on basic astronomy and quantum physics
- CrackerMcGinger
- · Replies 12 ·
Graduate How to measure CMB anisotropies *In Practice*
- astrolollo
- · Replies 2 ·
Graduate What laws of physics existed before the Big Bang?
- michaeljmj
- · Replies 15 ·
Graduate Does Gravity Gravitating Alter Cosmology?
- wolram
- · Replies 20 ·
Graduate Frame of reference: grade 2n vs. grade 2n-1
- eaglechief
- · Replies 2 ·
High School Why can't we measure Earth's absolute speed in space?
- hafiz ns
- · Replies 5 ·
Graduate Modified Newtonian Dynamics vs. Quantum Gravity
- sderamus
- · Replies 1 ·
What do you think about humans settling on the moon?
- @PK nd
- · Replies 78 ·
Undergrad Can Neutrinos Escape Black Holes?
- Stephanus
- · Replies 18 ·
Graduate Does space have a velocity in spacetime?
- eaglechief
- · Replies 5 ·
Graduate Finding Number of Stars that have Died
- astrofunk21
- · Replies 3 ·
Undergrad Why don't black holes become stars again?
- azhelton69
- · Replies 12 ·
Graduate How do you project a Sersic Profile into 3D?
- Earnest Guest
- · Replies 1 ·
Graduate Accurate measurement of z = 8.68 galaxy
- marcus
- · Replies 16 ·
Graduate Can We Measure the Probability of Order in the Universe?
- Morphsnorkle
- · Replies 8 ·
Graduate The Lords of the Rings among centaurs
- PF_SpaceNews
- · Replies 3 ·
Graduate How/Why does GR break down in Planck Epoch?
- Buzz Bloom
- · Replies 8 ·
Undergrad Calculating the observable universe size from light-year and age estimates
- samisbored
- · Replies 17 ·
Graduate What was the size of the universe between Planck time and inflation?
- clinden
- · Replies 7 ·
Stargazing Got my First Telescope | Celestron Sky Prodigy 130 | Astrophotography
- Glenstr
- · Replies 32 ·
High School Who discovered the cause of a red moon?
- Opus_723
- · Replies 3 ·
High School Why do comets have a dust layer on their surface?
- fred20
- · Replies 5 ·
Undergrad How much does weight affect re-entry into the atmosphere?
- stacks
- · Replies 1 ·
Graduate Can Higgs boson interactions help identify dark matter candidates like WIMPs and MACHOs?
- Quds Akbar
- · Replies 5 ·
High School Mars panorama from Curiosity shows petrified sand dunes
- PF_SpaceNews
- · Replies 1 ·
Graduate How much is popping into and out of
- udtsith
- · Replies 2 ·
Undergrad How do we determine distances of objects in space?
- AaromTheBritt
- · Replies 1 ·
Russian cosmonaut back after record 879 days in space
- PF_SpaceNews
- · Replies 4 ·
Graduate Questions re electroweak de-unification during inflation
- Buzz Bloom
- · Replies 2 ·
Graduate How can I apply probability to the cosmological constant?
- Shadowclan
- · Replies 2 ·
Undergrad Why Does Earth Appear Mostly Blue from Space?
- rootone
- · Replies 3 ·
Graduate Why did the Big Bang singularity expand to infinite space?
- Buzz Bloom
- · Replies 26 ·
High School Could time travel between parallel universes avoid the grandfather paradox?
- BadgerBadger92
- · Replies 2 ·
High School Why does Pluto revolve clockwise
- Saleh0003
- · Replies 5 ·
Is Galileo Similar to GPS?
- PF_SpaceNews
- · Replies 2 ·
Sweeping over the south pole of Mars
- PF_SpaceNews
- · Replies 1 ·
Undergrad Planet at the center of mass of a binary star system
- John Fluharty
- · Replies 4 ·
High School Could we throw stuff into space?
- kieyard
- · Replies 14 ·
Undergrad Moon's crust as fractured as can be
- PF_SpaceNews
- · Replies 7 ·
Graduate VSl theoreis and energy creation
- palmer eldtrich
- · Replies 1 ·
Undergrad Stochastic Matrices in Cosmology
- TRB8985
- · Replies 5 ·
Undergrad Astronomers find galaxy cluster with bursting heart
- PF_SpaceNews
- · Replies 3 ·
Graduate Underground magma ocean could explain Io's 'misplaced' volcanoes
- PF_SpaceNews
- · Replies 1 ·
SETI reborn—the new search for intelligent life
- PF_SpaceNews
- · Replies 2 ·
Where to find cosmic ray data from the sun
- Tone L
- · Replies 3 ·
Graduate Does Redshift Change Over Time for a Constant Recession Speed?
- JohnnyGui
- · Replies 11 ·
Undergrad Who first found the Heliocentric or Geocentric Distances
- Philosophaie
- · Replies 8 ·
Graduate Cassini confirms global ocean at Enceladus
- mfb
- · Replies 4 ·
Graduate Neutral hydrogen gas in galaxy clusters
- PF_SpaceNews
- · Replies 2 ·
Graduate Finding the One Degree Peak in a Power Spectrum
- gluon
- · Replies 15 ·
Graduate Oxygen is not definitive evidence of life on habitable extrasolar planets
- PF_SpaceNews
- · Replies 4 ·
Graduate How Do You Calculate Hydrogen Ionization Using a Metagalactic Radiation Field?
- astrofunk21
- · Replies 2 ·
Graduate How Can I Derive the Kepler Equation?
- Philosophaie
- · Replies 4 ·
Graduate Convert from Magnitude Density to Mass
- Earnest Guest
- · Replies 1 ·
Is the Milky Way Visible with a New Wide-Angle Lens in Sydney's Night Sky?
- davenn
- · Replies 8 ·
Graduate How dwarf galaxies form star clusters without dust and gas
- PF_SpaceNews
- · Replies 1 ·
Undergrad Which is more realiable: NED or SIMBAD?
- Earnest Guest
- · Replies 1 ·
China aims to be first to land probe on moon's far side
- PF_SpaceNews
- · Replies 5 ·
Graduate Celeste: A new model for cataloging the universe
- PF_SpaceNews
- · Replies 2 ·
Graduate Temperature difference measured in CMB first peak
- gluon
- · Replies 1 ·
Graduate Could Planck stars explain fast radio bursts?
- skydivephil
- · Replies 3 ·
Graduate How do I calculate the event horizon?
- Spring
- · Replies 3 ·
Undergrad Young gas giants fly close to their suns
- PF_SpaceNews
- · Replies 4 ·
Undergrad Is Dark Matter Present in the Milky Way Galaxy?
- Tony Stark
- · Replies 6 ·
Undergrad The Universe accelerating and light
- Jaami M.
- · Replies 11 ·
Graduate What are the best parameters for λCDM?
- Earnest Guest
- · Replies 19 ·
Undergrad Could a Tidal Lock Cause the Earth to Stop Rotating?
- tony1grendel
- · Replies 28 ·
Graduate Higgs cyclic model from Steinhardt, Turok, Bars
- palmer eldtrich
- · Replies 3 ·
Graduate Universe Expansion: What are the Limits?
- Tiago
- · Replies 1 ·
Graduate Time between farthest and closest distance from Jupiter
- Nathanael
- · Replies 1 ·
Graduate Does gravitational lensing depend on the wave or particle nature of light?
- Varun Lall
- · Replies 7 ·
Graduate Gravitational lensing and Dark Energy
- astrolollo
- · Replies 7 ·
Graduate Heory of Spacetime Curvature and Gravity
- twelfthroot2
- · Replies 6 ·
Undergrad Where Does Earth's Counter Gravity Go in an Expanding Universe?
- Ahmed Nabi
- · Replies 72 ·
Graduate Can Neutrinos Prevent Cavities?
- CygnusX-1
- · Replies 2 ·
Solar Tornado Captured by NASA's SDO Probe
- Mordred
- · Replies 3 ·
What can we learn about the Milky Way using an 85mm lens and static tripod?
- Andy Resnick
- · Replies 30 ·
Insights A Poor Man's CMB Primer Part 0: Orientation - Comments
- bapowell
- · Replies 4 ·
High School Is the Milky Way at the center of the expanding universe?
- Passionate Eng
- · Replies 7 ·
Graduate The Age Distribution of Intelligent Life in the Milky Way
- Chronos
- · Replies 5 ·
High School How did we know our galaxy is spiral?
- Passionate Eng
- · Replies 2 ·
Graduate Questions About Contact in the Movie
- skredp
- · Replies 28 ·
Graduate What information about inflation does the WMAP power spectrum provide?
- gluon
- · Replies 7 ·
Graduate What defines the surface of the Sun?
- Hornbein
- · Replies 2 ·
Undergrad Finding magnetometer data from Earth-orbiting satellites and ionosphere measurements
- Tone L
- · Replies 1 ·
Graduate Light in the expanding space universe
- Gerinski
- · Replies 13 ·
Graduate Does Zero Net Energy equal Zero Energy?
- Athanatsius
- · Replies 10 ·
Graduate Exact Classical Correspondence in Quantum Cosmology?
- Garth
- · Replies 6 ·
Graduate How Has General Relativity Evolved Over 100 Years?
- Garth
- · Replies 3 ·
Clear Space Technologies: Recycling & Repurposing Orbital Space Debris
- fr1t2
- · Replies 30 ·