Space telescopes revolutionize astronomy by overcoming Earth's atmospheric limitations. They provide clearer images, access to the full electromagnetic spectrum, and uninterrupted observations. These advantages enable groundbreaking discoveries about the universe's age, distant galaxies, and exoplanets.

Different types of space observatories, from optical to gravitational wave detectors, explore various cosmic phenomena. They study everything from star formation to black holes, pushing the boundaries of our understanding. Advanced techniques like interferometry and transit spectroscopy further enhance our ability to unravel cosmic mysteries.

Advantages of Space-Based Observations and Major Space Telescopes

Space vs ground observations

• Space-based observations:
  • No atmospheric distortion enables clearer images and higher resolution
  • Access to entire electromagnetic spectrum including infrared, ultraviolet, X-rays, and gamma rays
  • Continuous observations uninterrupted by day/night cycle or weather
• Ground-based observations:
  • Lower cost compared to space-based telescopes
  • Easier maintenance and upgrades can be performed
  • Larger telescope sizes possible due to fewer size constraints
  • Limited to visible light and some radio waves that pass through Earth's atmosphere
  • Use of adaptive optics to partially compensate for atmospheric distortion

Contributions of major space telescopes

• Hubble Space Telescope (HST):
  • Discovered age of the universe to be 13.8 billion years old
  • Observed distant galaxies and their evolution over cosmic time
  • Studied exoplanets and their atmospheres to understand their composition
  • Captured detailed images of planets (Jupiter), nebulae (Crab Nebula), and star clusters (Pleiades)
• James Webb Space Telescope (JWST):
  • Infrared observations of early universe to study formation of first galaxies and stars
  • Study of exoplanet atmospheres with potential for detecting biosignatures (methane, oxygen)
  • Observations of star and planet formation in stellar nurseries (Orion Nebula)
  • Imaging of faint, distant objects too dim for Hubble to detect

Types of Space-Based Observatories

Types of space-based observatories

• Optical telescopes (Hubble, Kepler):
  • Visible light observations to image planets, stars, galaxies, and other celestial objects
  • Studying the expansion of the universe by measuring distances to distant galaxies (redshift)
• Infrared telescopes (Spitzer, James Webb):
  • Observing cooler objects like planets, dust, and molecular clouds
  • Studying the early universe by detecting redshifted light from distant galaxies
  • Penetrating cosmic dust to reveal hidden stars and structures (Pillars of Creation)
• Ultraviolet telescopes (GALEX):
  • Observing hot, young stars that emit strongly in UV (O and B stars)
  • Studying star formation and evolution in nearby galaxies (Andromeda)
  • Investigating the interstellar medium and its composition (Orion Nebula)
• X-ray telescopes (Chandra, XMM-Newton):
  • Observing high-energy phenomena like black holes, supernovae, and galaxy clusters
  • Studying the hot gas in the universe, such as in the intracluster medium (Bullet Cluster)
• Gamma-ray telescopes (Fermi):
  • Detecting the most energetic events in the universe, including gamma-ray bursts and pulsars
  • Studying cosmic rays and their origins (supernova remnants)
  • Investigating dark matter through its potential gamma-ray emissions
• Gravitational wave observatories (LISA):
  • Detecting ripples in spacetime caused by massive cosmic events
    1. Merging black holes (GW150914)
    2. Colliding neutron stars (GW170817)

Advanced Space-Based Observation Techniques

• Space-based interferometry:
  • Combining light from multiple telescopes to achieve higher resolution
  • Potential for detecting Earth-like exoplanets and studying their atmospheres
• Cosmic microwave background observations:
  • Studying the oldest light in the universe to understand its early stages
  • Providing evidence for the Big Bang theory and cosmic inflation
• Exoplanet transit spectroscopy:
  • Analyzing the light passing through an exoplanet's atmosphere during transit
  • Determining atmospheric composition and potential habitability of exoplanets