Introduction and Monthly Reminders
July has continued the weather pattern from June, with hot temperatures but mostly clear skies. I enjoyed the typical sights of the night sky, mostly watching the Moon as it changed phase. I had every intention of taking some astrophotography images while I was out of town, but unfortunately, it didn't happen. I have another short trip planned for the second half of the month with the prospect of another evening of astrophotography.
The second half of July has a lot to offer stargazers. The New Moon phase is approaching, which will give observers the chance to view some DSOs, especially if a telescope is used. The Moon will pass close by all of the planets during the second half of the month. However, the most anticipated event of July, the Southern Delta Aquariid Meteor Shower, will peak on the 31st. Observers can already spot meteor streaks from this shower, with the rate increasing until the 31st. Observers may also start to glimpse meteors from the Perseid Meteor Shower, which will peak in early August. The overlap of the Aquariids and Perseids presents a unique opportunity for stargazers, whether they are purely watching for meteors or trying to capture images of them.
3I/ATLAS: The Interstellar Comet
A newly discovered object dubbed 3I/ATLAS has been detected moving through our solar system. It is so named because it is the third interstellar object (3I) ever detected and was discovered by the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) survey telescope located in Chile. This object was officially discovered on 01 July 2025 but has been seen on archived data dating back to 14 June 2025. As I sit here and write this report, 3I/ATLAS was unknown a month ago. Today, little is known about this object, but new information is becoming available daily.
This new object is known to come from outside our solar system due to its current trajectory. By running simulations, astronomers can see the path 3I/ATLAS is on and the direction from which it came, the constellation of Sagittarius. This object is also moving at an incredible speed, much faster than an object orbiting the Sun would achieve naturally. It is believed that 3I/ATLAS is made up of a large amount of water ice, but other physical properties, such as its size, are currently unknown. The water-ice makeup is similar to comets found in the Kuiper Belt, leading astronomers to classify 3I/ATLAS as an interstellar comet, the first of its kind!
Thought of being mostly comprised of water ice, 3I/ATLAS will begin to "thaw" as it approaches the Sun, growing a tail and having a nucleus and coma similar to those of a comet. Unlike comets that orbit the Sun, this interstellar object should not get close enough to the Sun to disintegrate. Based on its current trajectory, 3I/ATLAS will make its closest approach to the Sun in October, bringing it approximately 1.5 AU from our star. This places it between the orbits of Earth and Mars. No need to worry! As a reminder, the Earth is 1 AU from the Sun.
When 3I/ATLAS was discovered, it was travelling at a speed of 137,000 miles per hour! That's approximately 38 miles per second! That's the distance from Salt Lake City to Ogden! The velocity of 3I//ATLAS will increase as it approaches the Sun.
As 3I/ATLAS approaches the Sun and gets closer to Earth, more information about this first-of-a-kind interstellar comet will become available. This visitor is not expected to get very bright and will require a large telescope at a dark sky site to be seen. It should remain in view of Earthbound telescopes through September, at which point it will be too close to the Sun to view. Observations can resume in December when this interstellar comet is expected to emerge on the other side of the Sun.
It should be relatively simple to find updates on 3I/ATLAS as the information becomes available. I don't have a particular source that I know will keep their information current, but news feeds, however obtained, will provide this information. Enjoy the night sky through the rest of July and remember to keep looking up!
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| Now get outside and look up! |
