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Mercury magazine

Fall 2019 - Volume 48, Number 4

Fall 2019 - Volume 48, Number 4

Table of Contents



[9] Space News
A rundown of some of the most exciting developments in space and time.

[27] Cosmic Views, Jason Major
The solar system has a new dwarf planet and NASA continues to troubleshoot InSight’s mole woes.

[29] Passing Through, Steve Murray
Two interstellar travelers have visited the solar system in as many years—how many more are out there?

[34] The TMT: At an Impasse
As protests continue to stall construction of the Thirty Meter Telescope (TMT) on Hawaii’s Maunakea, where do we go from here?


[3] Perspectives, Ian O’Neill
A Spotlight on Hawai’i

[4] First Word, Linda Shore
The TMT: To Build or Not to Build

[6] Editor’s Journal, Ian O’Neill
The TMT: Science Lost

[15] Annals of Astronomy, Clifford J. Cunningham
Great Comet Confusion

[17] Astronomer’s Notebook, Jennifer Birriel
By the Light of Earth

[19] Armchair Astrophysics, Christopher Wanjek
Darkness Calls

[21] Education Matters, Brian Kruse
The TMT: It’s All a Matter of Perspective

[24] A Little Learning, C. Renee James

[40] Reflections, Ian O’Neill
Baby Stars Feed off Dusty Pretzel

Passing Through (Feature)

By Steve Murray

As giant planets orbit through the disks of young protoplanetary systems, their gravity can eject some pieces of disk material into interstellar space. Over the eons, chunks of planet-building debris (known as planetesimals) should have drifted through our galactic neighborhood, and astronomers have wondered where it was. All the asteroids and comets we had discovered to date seemed to be native to our solar system. Now, in the span of only two years, we’ve spotted two extrasolar visitors and a new analysis predicts that we can expect many more.

At an Impasse (Feature)

By Sarah Wells

Cold mountain winds whipped across hardened lava fields on July 15th as protestors bearing Hawaiian flags and winter coats took to the base of Hawaii’s sacred Maunakea to create a human barricade across the mountain’s single access road. Signs and banners reading “Protect Maunakea” and “Road Closed Due to Desecration” were held by both young and old kia’i, or protectors, taking a stand against what they believe to be the most recent in a long line of exploitative actions against Native Hawaiians: the building of the Thirty-Meter Telescope (TMT).

Say “Hi!” to Hygiea, the Smallest Dwarf Planet (Cosmic Views)

By Jason Major

This image, made from data captured with the SPHERE instrument on ESO’s Very Large Telescope (VLT), shows Hygiea, the fourth-largest object in the main asteroid belt. But more than just a random chunk of rock and rubble caught between Mars and Jupiter, Hygiea may very well become the newest member of the dwarf planet club.