A Visitor From Another Star System? A/2017 U1 Update for 10/27/17

TL;DR

A newly discovered object, possibly from another star system, has passed through our solar system, raising questions about interstellar comets and asteroids.

Transcript

It isn't often that I get to announce that a visitor from another star system might be passing through our solar system right now. This newly discovered object, known as A/2017 U1, appears, if its trajectory is indeed hyperbolic, that it is not gravitationally bound to the sun, meaning that it may have originated in entirely different star system. ... Read More

Key Insights

• 🤩 A/2017 U1 is a rare interstellar object passing through our solar system, possibly originating from another star system.
• ❓ The discovery of A/2017 U1 offers an opportunity to study the chemical compositions of other solar systems.
• 🧠 Interstellar dust and grains constantly rain down on Earth, and some have been collected by spacecraft and found in meteorites.
• 🪐 Capture of interstellar objects by planets like Jupiter is a possibility, providing insights into their origins.
• 🌃 The direction of A/2017 U1 suggests it might have come from the vicinity of Vega, a bright night sky star surrounded by dust and material.
• ❓ Determining the precise origin of interstellar objects is challenging and often impossible.
• ☄️ A/2017 U1 provides further evidence of the existence of interstellar comets and asteroids.

Questions & Answers

Q: What is A/2017 U1, and why is it significant?

A/2017 U1 is a newly discovered object that appears to have originated from another star system, making it one of the few known interstellar objects to pass through our solar system.

Q: How was A/2017 U1 detected, and why was it not discovered before passing by Earth?

A/2017 U1 was detected on October 18, after it had already passed by Earth. Its detection was challenging due to its dimness and the need for large telescopes.

Q: What does the absence of a coma suggest about A/2017 U1?

The absence of a coma suggests that the object is either a dead comet or an asteroid. An active comet would exhibit a coma as its ice evaporates.

Q: Is it possible for Jupiter to capture interstellar comets?

Yes, Jupiter's immense gravity can potentially capture interstellar comets. There are already two candidates, Comet Machholz 1 and Hyakutake C/1996 B2, with unusual compositions compared to other comets in the solar system.

Summary & Key Takeaways

• A newly discovered object, A/2017 U1, is not gravitationally bound to the sun and appears to have originated from another star system.

• Comets and asteroids from other star systems entering our solar system was anticipated, based on models of our own Oort cloud.

• A/2017 U1 is thought to be a dead comet or an asteroid, and its passing through our solar system offers an opportunity to study interstellar objects.