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 USGS Moon map with legend - can't enlarge the PDF
- KevinMcHugh
- · Replies 2 ·
Undergrad White dwarf Ultra-relativistic electrons
- Galaxer
- · Replies 9 ·
Undergrad Gauge transformation in cosmological perturbation
- Figaro
- · Replies 4 ·
Undergrad Can the Moon form a smiley face between Venus and Jupiter?
- swampwiz
- · Replies 17 ·
Undergrad Suggestion for resources about cosmic rays
- Endeavour13
- · Replies 1 ·
Graduate Can a single star with 6 to 8 solar masses end up as a supernova 1a?
- Fede
- · Replies 3 ·
Insights Dark Energy Part 3: Fitting the SCP Union 2.1 Supernova Data
- RUTA
- · Replies 0 ·
Undergrad The Bullet Cluster: 1E0657-56 vs. 1E0657-558
- Ranku
- · Replies 5 ·
Undergrad Elliptical Orbit and Kepler's equation
- DuckAmuck
- · Replies 1 ·
Insights Einstein-de Sitter cosmology and dark energy
- RUTA
- · Replies 10 ·
Insights Dark Energy Part 2: LCDM Cosmology
- RUTA
- · Replies 0 ·
High School Free Online Lecture: Seeing the Unseeable - Capturing an Image of a Black Hole
- atyy
- · Replies 5 ·
Undergrad Big Bang singularity: can we say anything about its size?
- iantresman
- · Replies 2 ·
Graduate Elliptical orbit parameterized by time
- DuckAmuck
- · Replies 5 ·
High School If the Universe keeps expanding this way, it gets torn apart
- A Middle Aged Man
- · Replies 19 ·
High School What Did Hubble See On Your Birthday?
- fresh_42
- · Replies 9 ·
Stargazing Wicked pink supermoon the other night Pics
- ETsmyhomeboy
- · Replies 4 ·
Stargazing Could these rocks be lunar or Martian meteorites?
- ETsmyhomeboy
- · Replies 18 ·
High School What is the Cooling Time of a Neutron Star?
- Thecla
- · Replies 3 ·
Undergrad How does Jupiter protect the Earth from collision with space rocks?
- Owen Ransen
- · Replies 2 ·
High School Why don't electrons fall into neutrons in neutron stars?
- Attu
- · Replies 6 ·
Undergrad How do we know dark matter follows ordinary gravity rules?
- zuz
- · Replies 16 ·
Undergrad Has the evidence for anisotropy of cosmic acceleration been discussed?
- Jorrie
- · Replies 2 ·
High School Why Do We See Old Galaxies in Every Direction?
- stuart100
- · Replies 12 ·
High School Lunar Crater Radio Telescope (LCRT)
- lomidrevo
- · Replies 1 ·
Undergrad Atmospheric pressure with depth on Mars at 0.35 and 0.7 bar
- Miles Behind
- · Replies 14 ·
Undergrad Objects flying over the lunar surface
- Glenstr
- · Replies 23 ·
Stargazing No, the Moon will Not be Pink Tonight
- russ_watters
- · Replies 4 ·
Undergrad To collect all info at the event horizon
- Chiron69
- · Replies 8 ·
High School How hard is it to detect extinct comets?
- xpell
- · Replies 3 ·
High School Meaning of Time / Space axes swapping (for Time)
- Grinkle
- · Replies 6 ·
Undergrad The life cycle of a star and the bell shaped energy emission curve
- kinchit bihani
- · Replies 11 ·
High School How can black holes move if time stops at their singularity?
- Psychonuclear
- · Replies 10 ·
Undergrad Velocity correction´ formula for the rotation of the Earth
- Ennio
- · Replies 3 ·
Undergrad Solar wind velocity and corrections
- Ennio
- · Replies 1 ·
Undergrad Who was the first to find an initial singularity in GR models of the universe?
- windy miller
- · Replies 7 ·
Undergrad A Puzzle Regarding the Time Between Consecutive March Equinoxes
- Buzz Bloom
- · Replies 30 ·
Insights The Evolution of the Universe, Cosmic Web and Connections
- Prof Mark R Smith
- · Replies 2 ·
Undergrad Can Dark Matter Exist in Higher Dimensions?
- Negativ3
- · Replies 50 ·
Insights Black Holes Are Not Empty Voids
- Prof Mark R Smith
- · Replies 11 ·
Undergrad Is Jupiter's core actually solid diamond?
- KevinMcHugh
- · Replies 10 ·
High School How old is the light from the Triangulum Galaxy?
- FrankC
- · Replies 6 ·
Insights Gaia and the Race to Detect More Gravitational Waves
- Prof Mark R Smith
- · Replies 1 ·
Undergrad What Does a Negative Value for the Deceleration Parameter Imply in Cosmology?
- redtree
- · Replies 1 ·
High School Is it possible to see the history of space if it expands faster than light?
- ramim
- · Replies 4 ·
Undergrad Understanding inflationary cosmology
- windy miller
- · Replies 4 ·
High School How much in the past do we see these planets?
- Dreksler
- · Replies 2 ·
Undergrad Is My Basic Understanding of Universe Expansion Correct?
- Onst
- · Replies 14 ·
Undergrad Why do particles at rest in comoving coordinates have Hubble flow velocity?
- Arman777
- · Replies 6 ·
Undergrad Comoving Reference Frame in Cosmology
- Arman777
- · Replies 2 ·
Graduate First MOND galaxy formation simulation and testing against different galaxy types
- fresh_42
- · Replies 8 ·
Undergrad Universal interferometric signatures of a black hole’s photon ring
- BillTre
- · Replies 1 ·
Undergrad Is the Brans-Dicke Vacuum Cosmology Theory Still Relevant?
- jcap
- · Replies 4 ·
High School Can Elon Musk's BFR Project Meet Its Ambitious Timeline for Mars Colonization?
- gleem
- · Replies 2 ·
Undergrad Where exactly is the Hertzsprung Gap?
- swampwiz
- · Replies 10 ·
High School Conjunction Mars, Jupiter, Saturn, Moon - March 18 + or -
- Tom.G
- · Replies 2 ·
High School What Does it Mean When We Say the Universe is 'Flat'?
- MikeeMiracle
- · Replies 3 ·
Undergrad Variations in Sun-Earth distance with a 2000-year cycle?
- Genava
- · Replies 7 ·
Undergrad Why do lunar perigees vary in frequency during 2020?
- ScottVal
- · Replies 12 ·
Undergrad If humamoids lived around a flare red dwarf, would the flare kill them?
- swampwiz
- · Replies 5 ·
Undergrad Coordinate dependence of recession velocities
- timmdeeg
- · Replies 12 ·
High School Could another Big Bang occur spontaneously in an expanding universe?
- kolleamm
- · Replies 10 ·
Undergrad A new space rock to my collection
- davenn
- · Replies 18 ·
High School Astrophysics research project topic for high school
- miafrasca_
- · Replies 13 ·
Undergrad This Wikipedia article about Scholz's Star doesn't make sense
- swampwiz
- · Replies 4 ·
Undergrad How Can the Newtonian Spherical Ball Be in Stable Equilibrium?
- Weran
- · Replies 15 ·
Stargazing Satellite grids around other planets
- Gear300
- · Replies 4 ·
Graduate Elliptical orbit and how seasons would be affected
- CosmicAdam
- · Replies 7 ·
Undergrad Is Big G and Dark Energy Constant Over Time?
- WhatIsGravity
- · Replies 38 ·
Stargazing Is there an official name yet for tau Ceti 'f'?
- Nik_2213
- · Replies 4 ·
Undergrad How do physicists know that an external world exists?
- fractalzen
- · Replies 3 ·
Undergrad Force needed to deflect a 0.5-mile asteroid with a nuclear explosion
- screamindivr145
- · Replies 7 ·
Graduate Inflation and measurement of cosmic bodies
- Negativ3
- · Replies 2 ·
Stargazing Why do we see distant galaxies as they were millions of years ago?
- TaurusSteve
- · Replies 8 ·
Undergrad What is the current understanding of supernova mechanisms in 2020?
- virgil1612
- · Replies 7 ·
Undergrad Why does the Universe have so many galaxies?
- Maximum7
- · Replies 20 ·
Stargazing What does the 'e' mean in scientific notation like 5.879e+12?
- TaurusSteve
- · Replies 3 ·
High School Tau neutrino flux in IceCube data
- Timboo
- · Replies 35 ·
Undergrad Tidal forces acting on planet NGTS-10b
- Buzz Bloom
- · Replies 2 ·
Undergrad Does the expansion of the Universe heat stars and bodies?
- Hypatio
- · Replies 13 ·
Undergrad Astronomers detect biggest explosion in the history of the Universe
- Timboo
- · Replies 15 ·
Undergrad Ptolemaic Model of the Solar System
- ZapperZ
- · Replies 12 ·
Undergrad Why didn't the early universe collapse into a black hole?
- Warp
- · Replies 12 ·
High School If space is transparent how can we not view light from a black hole
- Hi12
- · Replies 3 ·
High School How to calculate the energy released?
- kinchit bihani
- · Replies 3 ·
High School Why are there 4 dots in Einstein rings?
- Buckethead
- · Replies 11 ·
Stargazing How is absolute magnitude determined for Cepheid variables in the distance ladder?
- CPW
- · Replies 6 ·
High School Dark matter that doesn't gravitate?
- chirhone
- · Replies 12 ·
High School How Does Modern Particle Accelerator Energy Density Compare to the Big Bang?
- jeremyfiennes
- · Replies 6 ·
High School I don't understand the evidence or possibility of the Big Bang
- spacecapitalist
- · Replies 3 ·
Stargazing How much brighter is the Sun when viewed from space?
- ElliotSmith
- · Replies 9 ·
Undergrad Is There really a Hubble Tension?
- Arman777
- · Replies 10 ·
Stargazing Is a star's size changed due to gravitational deflection (lensing)?
- Forreal
- · Replies 15 ·
High School Why / How do we feel heat from the sun
- MikeeMiracle
- · Replies 7 ·
Undergrad Understanding the Age of the Universe
- Zeno Ether
- · Replies 8 ·
Undergrad Is there a distinction between angular resolution and angular discrimination?
- Physics Student 1234
- · Replies 1 ·
Undergrad LIGO+Virgo saw something unknown
- mfb
- · Replies 15 ·
High School Why Is There No New Data from LIGO/VIRGO?
- jimgraber
- · Replies 9 ·
High School Are Early Galaxies Indicating a Future Dead Universe?
- Timboo
- · Replies 4 ·
High School Learning to use a Solar Scope with an H alpha filter
- sophiecentaur
- · Replies 21 ·