Context: The European Space Agency (ESA) has unveiled the first images captured by the Euclid space telescope.
Euclid Space Telescope
- Euclid Space Telescope was launched on July 1, 2023 from Cape Canaveral in Florida on a SpaceX Falcon 9 rocket by the European Space Agency (ESA).
- The telescope is stationed 1.5 million km away from the Earth at the Lagrangian Point 2.
- It will observe the shapes, distances, and motions of billions of galaxies spanning over 10 billion light-years over the next six years.
Objective:
- To create the largest cosmic 3D map of the universe to better understand the distribution of dark matter and reveal the influence of dark energy in the early universe.
- Dark matter and dark energy together make up 95% of the universe.
- To understand the evolution of the Universe by looking at the light emitted from galaxies 10 billion years ago.
- Euclid is a 1.2 metre-wide telescope with a 600-megapixel camera to record visible light and a near-infrared spectrometer/camera and photometer to determine the redshift of detected galaxies.
Dark Energy
- Around 68% of the Universe is made of dark energy while dark matter makes up 27%. Only the remainder is composed of fermionic matter, i.e., things on the Earth, planets, stars, etc.
- Scientists theorised the existence of dark energy 25 years ago when a team of researchers found that instead of slowing down due to gravity (inwards pulling force), the expansion of the Universe was speeding up. Scientists hypothesised that this was happening due to a mysterious form of energy called dark energy.
- The expansion of the universe is accelerating. Previously, it was thought that the pull of gravity will either slow down or even retract the expansion.
- Dark energy has been hypothesised as a repulsive force — a sort of anti-gravity. As our universe is expanding, it indicates that Dark energy has a greater abundance than Dark matter.
- Dark energy is a property of space so it does not get diluted as space expands. As more space comes into existence, more of this energy-of-space appears. As a result, dark energy causes the universe to expand faster and faster.
- While Dark matter exerts a “pull” on the universe, Dark Energy has a contrasting expansionary effect.
Dark Matter
- Dark matter has not yet been observed directly. It does not interact with matter and is completely invisible to light and other forms of electromagnetic radiation making it impossible to detect.
- Scientists are confident it exists because of the gravitational effects it has on galaxies and galaxy clusters.
