Source: IndiaToday

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Context

• The European Space Agency's (ESA) Gaia spacecraft, launched in December 2013, has recently faced and overcome significant challenges in its mission to map over a billion stars in the Milky Way.

Details

Gaia Spacecraft

• Gaia was launched by the European Space Agency (ESA) on December 19, 2013, with the goal of creating the most detailed 3D map of our Milky Way galaxy.
• The mission aims to survey over one billion stars, providing precise measurements of their positions, distances, and movements​​.

Key Features and Capabilities

• Instrumentation:
  • Gaia is equipped with a billion-pixel camera, the largest ever used in space, and a 10-meter sunshield to protect its instruments from solar radiation.
  • The spacecraft's instruments measure the positions, brightness, and colors of stars with exceptional accuracy.
• Data Collection: Gaia repeatedly observes each star to track their positions, distances, and changes over time, enabling the calculation of their movements and properties​​.

Mission Objectives

• Galactic Census: Conducting an astronomical survey of over one billion stars to build a detailed 3D map of the Milky Way​​.
• Stellar and Galactic Evolution: Understanding the formation, structure, and evolution of the Milky Way by mapping different stellar populations and their origins​​.
• Planet Detection: Detecting thousands of exoplanets by observing the tiny wobbles in stars caused by gravitational pulls from orbiting planets, focusing on Jupiter-sized planets within 150 light-years of the Sun​​.
• Brown Dwarf Detection: Identifying brown dwarfs, substellar objects that failed to sustain nuclear fusion, aiding in the study of their formation and distribution​​.
• Asteroid and Comet Discovery: Cataloging minor planets, including asteroids and comets within our Solar System, providing data on their orbits and properties​​.
• Supernova Detection: Detecting around 100,000 supernovae, providing early warnings and enabling detailed studies of these stellar explosions, crucial for measuring cosmic distances​​.

Operational Challenges

• Micrometeoroid Impacts: Gaia has encountered challenges such as impacts from micrometeoroids, which can affect its instruments and data collection capabilities.
• Radiation and Solar Activity: Gaia also deals with the effects of cosmic radiation and solar storms, which can interfere with its sensitive equipment.

Contributions to Astronomy

• Stellar Motion and Structure: Gaia’s precise measurements of stellar positions and motions have provided unprecedented insights into the structure and dynamics of the Milky Way.
• Star Formation and Evolution: The mission's data helps in studying the life cycles of stars, from their formation in molecular clouds to their end stages as white dwarfs, neutron stars, or black holes. It also aids in identifying various star populations and their chemical compositions, shedding light on the galaxy's evolutionary history​.
• Exoplanet Discoveries: Gaia’s ability to detect exoplanets through astrometry (measuring the wobbles in stars caused by orbiting planets) has expanded our knowledge of planetary systems, particularly those similar to our own Solar System​​.
• Asteroid and Comet Studies: Gaia’s observations of asteroids and comets contribute significantly to our understanding of the small bodies in the Solar System. This includes tracking their orbits, sizes, and compositions, which are crucial for studying the history and dynamics of the Solar System​​.
• Supernova Alerts: By detecting supernovae in their early stages, Gaia provides valuable alerts to astronomers, enabling them to study these explosive events in detail. This is essential for measuring cosmic distances and understanding the life cycles of stars​.

Spacecrafts Similar To Gaia

Spacecraft	Agency	Launch Date	Primary Objective	Key Achievements
Gaia	ESA	2013-12-19	Create a 3D map of the Milky Way by surveying over one billion stars	Detailed 3D map of the Milky Way, insights into stellar and galactic evolution
Hipparcos	ESA	1989-08-08	Measure the positions and motions of stars to create a precise star catalog	First precise catalog of star positions, paved the way for Gaia
Hubble Space Telescope	NASA/ESA	1990-04-24	Observe the universe in visible, ultraviolet, and near-infrared light	Deep field images, discovery of dark energy, detailed study of galaxies and nebulae
Kepler Space Telescope	NASA	2009-03-07	Discover Earth-like planets in other star systems by observing transits	Discovery of over 2,600 exoplanets, revolutionized understanding of planetary systems
James Webb Space Telescope	NASA/ESA/CSA	2021-12-25	Observe the universe in infrared light to study the formation of stars and galaxies, and the atmospheres of exoplanets	First images of exoplanet atmospheres, detailed study of early universe and galaxy formation

Sources:

IndiaToday

PRACTICE QUESTION Q: Which of the following statements is/are true about the Gaia mission? Gaia is a space observatory mission of the European Space Agency (ESA) launched in 2013. The primary objective of Gaia is to map the Milky Way galaxy in three dimensions. Gaia is equipped with a large telescope that allows it to observe exoplanets around distant stars. The mission aims to create the most accurate and comprehensive 3D map of the Milky Way galaxy, including precise measurements of stellar positions, distances, and motions. Options:  A) 1 and 2 only B) 2 and 4 only C) 1, 2, and 3 only D) 1, 2, and 4 only Answer: D)