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 Star Photography: Can We See Stars as Disks?
- thetexan
- · Replies 4 ·
Graduate The Cosmological Principle means infinite Observable Universes
- chasmanian
- · Replies 17 ·
High School Expansion of the Universe and the fourth dimension
- Mingfei Li
- · Replies 13 ·
High School Would lightning be possible on brown dwarfs?
- mollwollfumble
- · Replies 5 ·
Undergrad How does the perihelion passage affect the orbital period of comet Neowise?
- Buzz Bloom
- · Replies 4 ·
Undergrad Is Triton ever hidden behind Neptune?
- Albertgauss
- · Replies 17 ·
High School What Are the Linear Dark Features on the Sun?
- mollwollfumble
- · Replies 5 ·
Solar System Dynamics page at NASA/JPL
- Tom.G
- · Replies 1 ·
High School Are the telescopes at Mauna Kea available for anyone to use?
- swampwiz
- · Replies 17 ·
Undergrad CMB creation, distance measurement question
- artis
- · Replies 7 ·
Undergrad How bright of a bolide would a Saturn IV-B stage be if it hit Earth
- swampwiz
- · Replies 4 ·
High School The Hubble Telescope Images a Magnificent Galaxy With “Flocculent” Spiral Arms
- Spinnor
- · Replies 3 ·
High School How was the amount of matter in the Universe determined?
- saddlestone-man
- · Replies 18 ·
High School Did energy begin to exist? Can energy exist without space and time?
- Nathaniel Fisher
- · Replies 3 ·
Undergrad Is the backward extrapolation of the expansion of the Universe valid?
- PhysicalAardvark
- · Replies 49 ·
Undergrad CCD Readout Noise vs Temperature
- Drakkith
- · Replies 11 ·
High School Why certain stars seem to move very little in the sky
- Ittiandro
- · Replies 56 ·
Graduate Collision-dominated plasma (stellar coronae)
- atomiclaser
- · Replies 5 ·
Undergrad How to measure a 21 cm EM wave if it is Doppler shifted?
- atomiclaser
- · Replies 1 ·
Undergrad Observing colour through telescopes
- PEGELLA
- · Replies 11 ·
Undergrad How can we observe black holes if nothing escapes them?
- homerwho
- · Replies 6 ·
Undergrad Wheeler's Mutability principle and multiple universes?
- Suekdccia
- · Replies 4 ·
Undergrad If a 4th dimension existed would universe expand anisotropically?
- jk22
- · Replies 2 ·
High School Could a Black Hole Power Civilization?
- MikeeMiracle
- · Replies 1 ·
Undergrad Black neutron star significance
- phinds
- · Replies 3 ·
Undergrad Could Dark Matter Be Present in Our Solar System?
- zuz
- · Replies 13 ·
High School How to prepare my camera for a solar eclipse
- Wrichik Basu
- · Replies 42 ·
High School Does the Universe really have to be at least as old as the oldest thing in it?
- Jupiter60
- · Replies 4 ·
Graduate Does FRW domain wall model in f(G) theory violate Lovelock theorem?
- Hatkar
- · Replies 1 ·
Undergrad Hypothetical Eclipse Calculation
- mahonskey
- · Replies 8 ·
High School Quantum total eclipse of the sun?
- mahonskey
- · Replies 3 ·
Undergrad Big bounce theory in light of the closed Universe finding
- user30
- · Replies 5 ·
Insights 3 Possible Models For Why Uranus Spins on Its Side
- Prof Mark R Smith
- · Replies 14 ·
Undergrad Do more impact craters always signify old age of a surface?
- Phys12
- · Replies 11 ·
Undergrad How Do You Derive Transverse Comoving Distance?
- S0uris
- · Replies 4 ·
Undergrad BICEP2's Mis-Estimation: Was Not CIB Subtraction the Cause?
- windy miller
- · Replies 2 ·
Undergrad Orbital velocity in the Schwarzschild metric
- Buzz Bloom
- · Replies 7 ·
High School What is Consciousness? How does it affect our Physical Universe?
- Immortal68
- · Replies 6 ·
Undergrad Does adding mass compress space in both directions from the mass?
- bkelly
- · Replies 4 ·
Undergrad Estimated distribution of mass and radiation across intergalactic space and galaxies
- Islam Hassan
- · Replies 4 ·
Undergrad If the Universe is closed, is it thereby self-contained as well?
- user30
- · Replies 27 ·
Undergrad X-ray Astronomy: Charged Ions Energy Distribution
- atomiclaser
- · Replies 3 ·
Undergrad Is the Universe bigger than we think?
- Trailblzn
- · Replies 5 ·
Stargazing Where does Earth's gravitational field end
- fascinated
- · Replies 24 ·
Undergrad Answers to a question about extraterrestrial life
- Buzz Bloom
- · Replies 5 ·
Undergrad What is the definition of foreground and background in astrophysical observation?
- atomiclaser
- · Replies 4 ·
High School What are the observable consequences of gravitational waves?
- Pennybags
- · Replies 2 ·
High School Why is Earth the only habitable planet in our solar system?
- jim mcnamara
- · Replies 12 ·
Graduate N-body simulation with varying neutrino mass
- Arman777
- · Replies 1 ·
High School Half of the Universe’s ordinary matter may have been found
- gmax137
- · Replies 3 ·
Undergrad Persistent features of astronomical bodies
- MrG99
- · Replies 3 ·
High School Lensing Gravitational Waves Like Light?
- sbrothy
- · Replies 4 ·
Undergrad Conservation of energy in cosmology
- windy miller
- · Replies 3 ·
Undergrad A cold, massive, rotating disk galaxy 1.5 billion years after the BB
- Tendex
- · Replies 1 ·
Graduate How to see if a cosmological model is flat?
- Philip Land
- · Replies 4 ·
Undergrad Power output of red dwarfs turning yellow and blue?
- bbbl67
- · Replies 2 ·
High School Feasibility of Yuri Milner's Breakthrough Starshot
- Quotidian
- · Replies 3 ·
Undergrad What is column density in astronomy?
- ray_mcintos
- · Replies 2 ·
Undergrad Will galaxies in a cluster eventually merge into one?
- Buzz Bloom
- · Replies 8 ·
Stargazing Backyard astronomers, how do you decide what to look at?
- Nick-stg
- · Replies 43 ·
High School Behavior of compasses AFTER the magnetic pole
- jaumzaum
- · Replies 3 ·
High School How long would a black hole take to consume a planet?
- Ryan_m_b
- · Replies 24 ·
Undergrad Trying to grok the draconic year
- swampwiz
- · Replies 2 ·
High School If the universe started from a point, must it be finite?
- stuart100
- · Replies 17 ·
High School How does emergent spacetime work?
- wolram
- · Replies 34 ·
Undergrad The picture of the Comoving coordinate
- Arman777
- · Replies 5 ·
Undergrad Curvature of Space in the Context of Cosmology
- Arman777
- · Replies 3 ·
Undergrad Does a neutron star collapse to singularity or remain inside its Schwarzschild radius?
- Tanelorn
- · Replies 17 ·
Undergrad Constant Curvature and about its meaning
- Arman777
- · Replies 9 ·
Undergrad The Cosmological Principle and the Universe
- greswd
- · Replies 6 ·
Undergrad Possible illogicalness of a 3-sphere shape of the Universe's space?
- greswd
- · Replies 35 ·
Stargazing Wasp-76b is a planet where it rains iron
- TaurusSteve
- · Replies 41 ·
Undergrad What percent of the universe is outside of galaxies?
- deltapapazulu
- · Replies 20 ·
Undergrad Could life on Earth survive if ejected from the solar system?
- mark!
- · Replies 16 ·
Undergrad What stars were observed @ 1919 solar eclipse to prove relativity?
- swampwiz
- · Replies 4 ·
Undergrad What are the lobes in the M87 black hole image?
- EN2
- · Replies 22 ·
Undergrad The effect of Faraday braking on the Earth’s orbit
- jeffkosmo
- · Replies 5 ·
Undergrad Can the multiverse hypothesis be an explanation for life on Earth?
- bland
- · Replies 7 ·
Graduate Is this evidence that Venus originally had a nitrogen atmosphere?
- JayS0
- · Replies 10 ·
High School If the Multiverse is correct why don't they appear inside our own?
- Chris Gascoigne
- · Replies 34 ·
High School Why does light from a falling observer appear redder near a black hole's horizon?
- RJ Emery
- · Replies 4 ·
Undergrad IAU Rotational Models: Sol Solar System Planet Info
- Sword7
- · Replies 4 ·
Undergrad Why the center of black holes should be different from neutron stars?
- Leonardo Muzzi
- · Replies 26 ·
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 ·