Astronomy, Astrophysics, Cosmology Forum

High School Can light from a star 14 billion light-years away reach Earth?

Graduate Size of the universe from a different perspective

Graduate How tall could trees grow on planets with different gravity?

Graduate Can we harness vacuum energy like the Casimir effect spring?

Graduate Space-Time Topology Theory: Learn About Popular Theories

Graduate Is Gravity Geometry or Quantum in Nature?

Undergrad Conversion of healpix fits file to normal fits file

Graduate Ozone formation timescale and evolution of complex life around different star types

High School Is it possible to reach absolute zero?

Undergrad Dark Energy Project: Studying the Universe

Undergrad Why Do Stars and Galaxies Keep Spinning?

High School About the Earth's orbital velocity

Graduate Baryon asymmetry and conservation of charge

Graduate Why is there one extra baryon per billion antibaryons?

Graduate Solving Extinction and Reddening in Photometric Analysis of M5 Globular Cluster

Graduate How do you derive the tidal force equation?

Graduate Estimating Planetary Cooling Times

Undergrad How to calculate the position of stars

High School Earth's distance from the galactic center?

High School Classification of Stella Spectra

Graduate Understanding Hagedorn Temperature: Can Light Speed Up?

High School Moon's Orbit: Moving Closer or Farther From Earth?

Graduate Proof of three dimensional space

Graduate Our sources of fear/anguish; permitted by the physical universe.

Stargazing Venus and Mars: Did They Ever Cross Paths in a Terrestrial Eclipse?

Graduate Can a solar sail reach another star against its radiation pressure?

Graduate Is the CMBR Truly Uniform?

Undergrad I'm confused about 1st Kepler's law and the 2 body problem

Undergrad "Estimating the Age of a Black Hole"

Stargazing Magazines about telescopes and astronomy

High School Why doesn't the asteroid belt block our view of the jovial planets?

Undergrad Can Obama's space policy fund both manned and robotic NASA missions?

Undergrad Why does Mercury's perihelion advance?

Graduate Where is the energy coming from to push space apart?

Graduate Is 'real space' merely a convenient mental representation?

Undergrad Why is the density of Mercury 40% larger than the density of Mars?

• Poll

High School Will the sun eventually die in 4.4 billion years?

Graduate Ways to accommodate modern cosmology

Graduate Have You Considered Dr. Oliver Manuel's Neutron Star Model for the Sun?

High School The most distant object that can still orbit the Earth.

Graduate Existence of a small planet (theoretically)

Graduate What is the average density of a rocky world according to Nilssen's Law?

Undergrad Have gravitational waves been detected or are they still theoretical?

Graduate Proto-Earth was ~230 Earth Masses

Graduate Astro- modelling a white dwarf via polytrope

High School Confusion over gravity and tides

Graduate Dark Matter in the solar system.

Graduate What is Nilssen's Law of Stars and how does it relate to star data?

Undergrad Does charge depend on the mass of a black hole?

Graduate Confusion regarding jargon in journals

Undergrad Why are stars often found far from their birthplace in nebulas?

Graduate Which from scratch? (group survey)

Graduate Is the Net Density of Any Space Interval Ever Zero?

Graduate Olbers' Paradox, the CMB and the observable universe

Graduate Why Dark Matter and Dark Energy?

Undergrad Google calculator impact on basic cosmo explanations

Undergrad Kepler's 3rd law to determine mass of jupiter

Undergrad Why isn't space at absolute zero if it's a vacuum far from stars?

Graduate Unique Roche limit and Saturn's rings

Graduate Age and metallicity of Population I stars?

Graduate Modelling density as a function of time?

Graduate Angular momentum conservation in a collapsing universe

Graduate Questions about Black Holes And Time

Graduate Is Space Real? The Existential Question of the Universe

Graduate Dimensions greater than the third?

Graduate Hawking Raditation and particle-antiparticle pairs

Graduate Recession of M81 and the M81 Group?

Undergrad The Stephan's Quintet and Arp's Theories

Graduate What Are the Six Puzzles Challenging LCDM Cosmology?

Graduate Dark energy, vacuum, and uncertainty

Undergrad Does Empty Space Contain Mass and Energy?

Graduate Can photons create black holes despite being massless?

High School Planetary Alignment: Will It Affect Us?

High School How did Earth end up with exactly the right mass and velocity to orbit the sun?

Graduate Age and structure of the Universe

Undergrad Paper topic ideas for cosmology class

Stargazing How does telescope illumination depend on mirror diameter and focal length?

Graduate Dark photons and the structure of the dark sector

Graduate Why Does Dark Matter Cause the Flattening of Galaxies' Discs?

High School Stars in the Western sky in early evening

High School Why Do Planets Travel in Elliptical Orbits Around the Sun?

Graduate Role of magnification and plate scale in professional telescope imaging

Undergrad Solar Wind and Its Impact on Planets

High School How Can You Identify Meteorites?

Graduate Galaxy clusters show unexpected motion beyond cosmic expansion

Graduate Calculating Observable Universe Mass in the Lambda-CDM Model

Graduate Building a Universe: Is Matter, Energy Purley Information?

Undergrad What are the benefits of using interferometry for exoplanet hunting?

Graduate Could Dark Matter Form Planets and Stars?

Graduate Is the Universe Homogeneous or Isotropic?

Undergrad What Prevents Air from Flowing Out of Earth's Atmosphere?

Graduate Can Dark Matter Be Utilized for New Technologies and Applications?

Graduate Large-scale Cosmic Flows & Moving Dark Energy: Beltran Jimenez & Maroto

Graduate How do big bang and black hole singularities differ and how small can matter compress?

High School A star for every grain of sand.

Undergrad What Atmosphere Would a Metal Planet Have?