The Universe’s Clock – What the Stars and Cosmic Expansion Tell Us
The question of the universe’s age has been a riddle for scientists and a source of wonder for philosophers since forever. According to the principles of modern cosmology, the figure is considered to be 13.8 billion years. This amount was determined by using different tools, such as studying the expansion and the oldest celestial beings within it.
From 100 Billion to 2 Trillion – The Mind-Blowing Number of Galaxies
The cosmos is so immensely huge, brimming with infinite galaxies that differ in size, pattern, and makeup. Researchers have spent many years trying to calculate the total number of galaxies, but because of our observing technology, we are able only to make reasonable conjectures.
With the help of advanced telescopes like the Hubble Space Telescope and the James Webb Space Telescope, astronomers have been able to refine their estimates significantly. While early calculations suggested there were around 100 billion galaxies, later research pushed this number to as high as 2 trillion. However, recent findings indicate that the actual number could be somewhere in between. So, how do astronomers estimate this number, and what challenges do they face?
Counting the Stars – Estimating the Cosmic Vastness
When you direct your gaze toward the night sky during a clear evening, countless stars become visible, which presents a breathtaking spectacle. The night skies above rural regions appear densely populated with innumerable luminous points that extend endlessly into the distance. The quest to determine the precise quantity of stars has presented astronomers with a persistent and formidable challenge throughout history. Despite the absence of a definitive answer, scientific estimates deliver valuable insights into the universe’s immense scale.
The First Mission to Land on a Come
The Rosetta space probe was launched on March 2, 2004, by the European Space Agency (ESA). Named after the famous Rosetta Stone that helped European researchers translate Egyptian hieroglyphics, it was the first time a mission was sent into space with the goal of orbiting a comet and then landing on it.
While the name alluded to the fact that this mission aimed to shed light on subjects that had long fascinated scientists, it was also based on the fact that the craft carried 6,500 pages of language translations that had been micro-etched onto a nickel prototype of the Rosetta Stone.
A Space Adventure Like No Other in the Universe
Being one of the most ambitious missions under the auspices of the European Space Agency, the Rosetta Mission aimed to study Comet 67P/Churyumov-Gerasimenko, henceforth referred to as simply 67P, up close.
Scientists will know, in that way valuable information about its composition and structure, its behaviors. Comets are material remains from the early solar system. Thus, the investigation of such bodies might give clues to scientists into processes that led to the creation of planets and other space bodies.
But it was Rosetta that first orbited a comet and then sent a lander, the probe Philae, onto its surface. The mission lasted for more than 12 years and revolutionised cometary science, making a number of discoveries that remain the foundation on which our understanding of the solar system is based.