Core Viewpoint - Astronomers have observed a new interstellar object, 3I/ATLAS, which is the third such "interstellar visitor" discovered to date, traveling through the solar system at high speed [1][5]. Group 1: Discovery and Characteristics - The ATLAS telescope, funded by NASA, first reported the discovery of 3I/ATLAS on July 1, 2023, initially marking it as object A11pl3Z before officially naming it [3]. - The calculated orbital eccentricity of 3I/ATLAS is 6.2, indicating it originates from outside the solar system, with a speed exceeding 60 kilometers per second as it traverses the solar system [3]. - Current observations suggest that 3I/ATLAS exhibits characteristics typical of comets, although its exact size remains undetermined, with estimates suggesting a diameter of around 20 kilometers [3]. Group 2: Scientific Implications - A research team led by Matthew Hopkins from Oxford University posits that 3I/ATLAS may be an older celestial body than those in the solar system, potentially originating from the galactic thick disk, which contains older stars [4]. - The likelihood that 3I/ATLAS is older than the solar system is estimated at two-thirds, with the possibility that it has been drifting in interstellar space for a significant period [4]. Group 3: Future Observations - As of now, 3I/ATLAS is located approximately 465 million kilometers from Earth and 600 million kilometers from the Sun, expected to reach its closest point to the Sun at about 210 million kilometers around October 30, 2023 [5]. - The interstellar object is projected to come closest to Earth in December 2023, at a distance of approximately 270 million kilometers, posing no threat to Earth [5].

Core Viewpoint - A new comet named SWAN is rapidly approaching the Sun, expected to reach its closest point to the Sun on May 1, with an estimated brightness of around magnitude 7 [1][3]. Group 1: Comet Characteristics - The SWAN comet was first observed by the SWAN camera on the European Space Agency's SOHO spacecraft in late March and was officially named "C/2025 F2 (SWAN)" by the International Astronomical Union on April 10 [1][2]. - The comet has a parabolic orbit with an eccentricity of 1.0000995, indicating it will not return after its close approach to the Sun [1][2]. - SWAN is characterized by its green appearance due to diatomic carbon in its coma, which reflects sunlight [2]. Group 2: Observational Details - The comet is currently moving from the northern hemisphere towards the southern hemisphere, with its closest approach to the Sun occurring at approximately 50 million kilometers, within the orbit of Mercury [2]. - It is expected to be observable from the northern hemisphere until around May 8, after which it will become increasingly difficult to see as it moves southward [2]. - There is uncertainty regarding the comet's stability as it approaches the Sun, with potential for disintegration due to solar heat, which has already been observed to some extent on April 20 [2]. Group 3: Public Observation - If the SWAN comet survives its close approach, it can be observed using binoculars or telephoto lenses in early May after sunset [3]. - The public is encouraged to check for the latest updates on the comet's status as it approaches the Sun [2].