Skywatch: Unique lunar eclipse will grace Hawaii skies

Featured Mauna Kea Observatory discovery

Astronomers using the Gemini Observatory on Mauna Kea are pulling apart a mystery surrounding two galaxies that collided 25 million to 30 million years ago, informally known as the “Taffy Galaxies” for their twisted shape.

While galaxy collisions are transformative events that can lead to the formation of molecular clouds populated with newly forming stars, the collision of UGC 12914 and UGC 12915 appears to have resulted in a different kind of structure: a bridge of highly turbulent material spanning the two galaxies.

Though this intergalactic bridge is teeming with star-­forming material, its turbulent nature is suppressing star formation. Learn more about this unique research through the observatory’s news release at noirlab.edu/public/news/noirlab2308.

Special events

In the early hours of Friday, isle observers will be able to view a partial penumbral lunar eclipse.

This occurs when the moon passes through the outer sections of Earth’s shadow, known as the penumbra. Instead of turning red, as it would during a total lunar eclipse, the moon will take on a darker color.

While the prime viewing locations for the full penumbral eclipse will be India, China, Australia and the areas in between, in Hawaii observers will see a partial eclipse where the upper third of the moon will appear dark.

The maximum eclipse will occur at 5:52 a.m. The moon will set in the west while the eclipse takes place.

Evening observations

As the sun sets, two planets, Venus and Mars, will stand out through dusk in the western sky. Venus will be easier to find as it is the third-brightest object in the sky after the sun and the full moon.

Higher in the sky, observers will also be able to find the red planet Mars.

Venus and Mars are the two planets in the solar system that are most similar to Earth. Venus is almost the same size as Earth; however, as it is so much closer to the sun, it is exposed to more heat and energy.

Venus’ proximity to the sun triggered a runaway greenhouse effect where the liquid water on the planet evaporated and mixed with various gases escaping from its volcanoes. This created an incredibly thick layer of clouds that traps heat and makes Venus the hottest planet in the solar system.

While Venus experiences a runaway greenhouse effect, Mars has the opposite problem. As Mars is much smaller, about half the size of Earth, it was unable to maintain its geological activity. This triggered a series of climate change events leading to a runaway icehouse effect, where the carbon dioxide is slowly depleted from the atmosphere. The runaway icehouse effect in the Martian atmosphere caused the overall temperature of the planet to get colder and colder.

As the navigational star family Kekaomakali‘i prepares to set in Komohana (the west), the next navigational star family — Kaiwikuamo‘o, the backbone — will rise in Hikina (the east).

Kaiwikuamo‘o is significant as it stretches all the way from Hokupa‘a, the North Star, through Nahiku, the Big Dipper. It then follows the arc of Nahiku to Hokule‘a and Hikianalia, then passes through Me‘e where it drops straight down to Hanaiakamalama, the Southern Cross.

The best time to view Hanaiakamalama will be when it is standing straight up in the sky just after 9 p.m. When Hanaiakamalama is in this position, it is used to make measurements with the horizon so that Hawaii navigators can precisely know where they are.

Morning observations

Early-bird stargazers will enjoy a very different perspective of the night sky.

As summer approaches, the sun will rise earlier and the nights will get shorter. Throughout May the sun will rise just before 6 a.m., and the light of dawn will color our sky starting around 5:30 a.m.

In the early morning hours, the faint planet Saturn will be high in the southeastern sky while the bright planet Jupiter will rise on the eastern horizon. Later on in the month, starting around May 15, careful observers will also be able to catch Mercury as it rises with Jupiter.

While the planets will stand out in the eastern sky, the notable shape of Kama­kaunuiamaui, Maui’s Fishhook, will be setting in the west. This recognizable shape of stars will be sitting in front of the “bulge” of the Milky Way where astronomers study the central regions of our galaxy.

May 2023 Sky Watch by Honolulu Star-Advertiser

The ‘Imiloa Astronomy Center of Hawaii is a center for informal science education at the University of Hawaii at Hilo showcasing astronomy and Hawaiian culture as parallel journeys of human exploration.