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Mapping the Universe: The Rubin Telescope and Its Ambitious Survey

Various astronomical observatories, including the Hubble Space Telescope and the James Webb Space Telescope, have undertaken efforts to create a comprehensive map of the cosmos by analyzing images of galaxies. However, the Rubin Observatory’s approach is set to surpass existing endeavors. With the capability to analyze billions of galaxies, the Rubin team aims to provide unparalleled precision and scale in their survey, as noted by Andrés Alejandro Plazas Malagón, an operations scientist at SLAC National Laboratory. “We’re going to have the widest galaxy survey so far,” he emphasizes.

Central to this ambitious project is the Large Synoptic Survey Telescope (LSST), equipped with an impressive 3.2-billion-pixel camera. The LSST features the largest focal plane in the field of astronomy, allowing it to capture extensive sections of the night sky efficiently.

The telescope’s innovative design allows it to change its orientation approximately every 34 seconds. This frequent repositioning enables astronomers to survey the entire sky every three nights. Steven Ritz, a project scientist at the University of California, Santa Cruz, explains that the LSST will revisit each galaxy about 800 times during its operational life. These repeated observations will enhance the ability of researchers to accurately measure the distortions of galaxies, contributing to a refined understanding of the dark matter web. “We’re going to see these galaxies deeply and frequently,” Ritz states. “That’s the power of Rubin: the sheer grasp of being able to see the universe in detail and on repeat.”

The overarching objective of this project is to compare the resulting map with existing models of dark matter. The most widely accepted theory, known as the cold dark matter model, posits that dark matter moves slowly in relation to light and interacts with regular matter primarily through gravitational forces. Alternative theories suggest different interactions and behaviors of dark matter. Each theory presents its own depiction of how dark matter aggregates around galaxies. By juxtaposing its findings against these theoretical models, the Rubin Observatory has the potential to validate some hypotheses while discrediting others.

A Cosmic Tug of War

In exploring the dynamics of dark matter and dark energy, a metaphorical framework emerges. Plazas Malagón describes dark matter and dark energy as engaged in a “cosmic tug of war.” On one side, dark matter acts like a magnet, drawing matter together, while on the other, dark energy works to push them apart.

The existence of dark energy was revealed in the late 1990s when astronomers observed that not only is the universe expanding, but the rate of this expansion is accelerating. As galaxies drift away from one another at increasing speeds, understanding the balance between these two cosmic forces—dark matter and dark energy—becomes crucial for unraveling the mysteries of our universe.

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