Tuesday, 25 May 2021

The Last Stargazers

Finished May 18
The Last Stargazers: The Enduring Story of Astronomy's Vanishing Explorers by Emily Levesque

This is a fascinating look at the modern history of astronomy and the different ways astronomers examine the universe. The author, Emily Levesque is an astronomer and included here are her own experiences.
The first chapter includes her first experience at an observatory telescope, an opportunity related to her summer project in her sophomore year at MIT. This project launched her career interest in red supergiants, and the science of dying stars. Here we learn of the practicalities of how observing is done, how these large telescopes are managed and see into the personal side of this career.
The second chapter looks at the technical side of things, explaining what the prime focus is, and how time on the telescopes is assigned. It also looks at some of this wild experiences that people have had when things don't go as expected. 
The third chapter looks at how things like weather affect observing time, starting with a windy night that meant that Emily wasn't able to take advantage of the clear skies on offer. It also talks about the access to observatories, which are located in remote, high altitude locations, with no lighting. (In most cases, even using the car headlights when driving at night is not allowed.) She also discusses the different kind of data that you might be gathering for later analysis. Reading this chapter made me wonder how astronomers are working during Covid with the limitations on travel.
The fourth chapter looks at other reasons that your time on the telescope might be lost. From natural disasters such as volcanoes and earthquakes, to fires, insects, and animals. Animals also sometimes add to the adventure, from bears and skunks to tarantulas and scorpions.
The fifth chapter looks at things like rules in the areas near telescope locations that limit certain activities to lessen interference, from lack of WiFi and cellphone reception to limitations on fuel for vehicles. It also looks at some physical failures, when telescopes have collapsed. A few months after this book was published, the Arecibo telescope collapsed. She also discusses other physical failures and injuries to staff.
The sixth chapter looks at other obstacles to observing from sex, age, and race to groups arguing against the building of observatories or access, including environmentalists and hunters to land rights activists. She looks at some legal cases, and some where listening and collaboration resolved the issues. 
The seventh chapter introduces the VLA (Very Large Array) telescopes and how they work. These are radio telescopes and they work in groups, which can even include other VLA telescopes in other parts of the world for certain projects. And of course they operate even during the day, since they don't need darkness for their data gathering. I learned that while weather doesn't affect them as much, things like birds can be issue. 
The eighth chapter introduces telescopes that are brought to higher levels of the atmosphere in planes and can therefore see things that our atmosphere filters out. The telescope is mounted in it's own compartment on a giant ball bearing. This ensures that it remains steady and that a door can be opened during flight to have the telescope open to the sky. She describes some of the limitations and safety issues this brings and talks about other higher atmosphere telescopes, both in aircraft and those launched by balloon. 
The ninth chapter talks about special observations, such as eclipses including the lunar and solar ones we often hear about as well as ones by smaller objects such as asteroids. This chapter also details some of the access issues that occur when timing becomes a big part of the observing data.
The tenth chapter introducing the subject of gravitational waves and how they are observed. It also introduces another kind of observatory, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and its unique design and features. 
Chapter eleven looks at supernovae and the importance of confirming observations, and chapter twelve looks at how the automation and remote control of some observing has begun, eliminating the need to travel and observe on site. Chapter thirteen goes even further down this road, showing how computer controlled telescopes optimize observing time by scheduling jobs efficiently and prioritizing observing based on its nature and relationship to other jobs in the queue. 
A lovely addition to this book is a reading group guide at the back with some suggested discussion questions. 
This book was written in a very accessible narrative style that makes this science understandable to the average reader. A fantastic read.

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