Authored By: ʻImiloa Astronomy Center

Featured Maunakea Observatory Discovery

Astronomers using the Subaru Telescope and Canada France Hawaii Telescope (CFHT) on Maunakea discovered a fossil of our early Solar System nicknamed “Ammonite”. This type of object is a sednoid, a group of small bodies with peculiar orbits around the edge of the Solar System and well beyond the gravitational influence of Neptune. Astronomers first discovered Ammonite using Subaru’s Hyper Suprime-Cam. They then took additional observations with CFHT’s MegaCam. 

Using data from these two Maunakea telescopes along with archival data from other observatories, astronomers determined Ammonite’s orbit. Ammonite appears to have a markedly different orbital orientation compared to other sednoids.  This orbital difference suggests our solar system is more diverse and complex than previously thought.  Additionally, it provides evidence against the Planet Nine hypothesis, which predicts that a distant, Neptune-like planet exists at the edges of the Solar System.

The researchers also conducted numerical simulations of Ammonite’s orbit and found that its orbit remains stable for the age of the Solar System of about 4.5 billion years. This provides evidence that Ammonite’s orbit has probably changed very little since the formation of the Solar System and makes Ammonite a “fossil” of the early Solar System.

More information can be found at the following press releases:

https://subarutelescope.org/en/results/2025/07/14/3574.html

https://www.sinica.edu.tw/en/news_content/55/3226

Special Events

Perseids Meteor Shower - August 12-13

The Perseids meteor shower decorates the sky each summer from late July through August. A peak of activity will occur on the night between Aug. 12-13, with up to 60 meteors per hour.  The shooting stars of this meteor shower are the remnants of material left from the comet Swift-Tuttle. When this comet last passed through the inner solar system in 1992, it left behind a cloud of dust and ice in the orbit of the planet Earth. Every year when the Earth passes through this debris cloud, the dust and ice fall through our atmosphere and burn up creating the shooting stars of the Perseids meteor shower. The shooting stars will roughly originate from the constellation of Perseus rising in the Northeastern sky. 

Evening Observing

At sunset, Mānaiakalani will be at its zenith and Kaʻiwikuamoʻo will begin to creep closer to our western horizon through August, showing that we are now beginning to enter fall. After sunset, as we look toward the direction of hikina (east), we are able to see the western half of Kalupeakawelo rising with the two chief stars Kākuhihewa (Scheat) rising in ʻĀina Koʻolau and Keawe (Markab) rising in Lā Koʻolau.

Morning Observing

At 6am Kekāomakaliʻi will be up in the night sky before the sun rises in the house of Lā in the Koʻolau (Northeast) quadrant, and in the west half of the night sky we can still see Kalupeakawelo.