Attending were members Russell Clark, Jack Gelfand, Carson Hanrahan, Mark Lasher, Chris Parent, David Manchester, Craig Snapp, Russ Pinizzotto, Gregory Shanos, Ron Thompson, Patrick Connolly, Jon Wallace, Greg Thorup, Jahna Romano, John O'Donnell, Al DiSabatino, Kevin Kane, Paul Howell, Ted Hebert, Maame Andoh, Robert Burgess, Scott Lovejoy, George Bokinsky, Joe Long, Ralph Lorenz, Roy Reigel, James Hummer, Anita Devito, Howie Marshall, Paul L Sasso, Kat Taylor, Dale Dermott, Forrest Sumner, Robbie Robinson, Brad Irish, Doug Lund-Yates, Jeremy Wright, John Saucier, Robert Dodge, Judy, Bob, Dwight Lanpher, David Gay, Dave Wallace, Earl Raymond, Russell Clark and the speaker, Dr. Ralph Lorenz.
Announcements
- Rob welcomed new members: Mark Renolds, Ben Barker, Russell Clark, and Robbie Robinson.
- At least 34 people have renewed their membership, but 52 haven't. Those who haven't should reach out to Al DiSabitano if they have any questions and be sure to renew their membership.
- The next club meeting is Thursday, Feb 2, featuring Jack St. Louis from the Vermont Astronomical Society discussing the Vermont club and providing some basics on Astronomy. This meeting, combined with March’s meeting on Greek and First Nations’ mythology, will be great programs for those newest to astronomy.
- The club hopes to resume star parties in March or April, so watch for announcements.
- A new comet may become visible (although best seen with binoculars) in the constellation Camelopardalis (the “Giraffe”) around Feb 1. Comet C/2022 E3 should be visible in the early morning (around 4 a.m.) in the area above the Big Dipper.
- Russ Pinizzotto will be giving a talk on Maine Winter Skies for the Maine Senior College at Noon on Jan 18 at Curtis Memorial Library in Brunswick.
- There will be a club directors’ meeting later this month. Notification will be provided and all members are welcome to attend.
Reports from Club Members
Russ Pinizzotto excitedly informed the club that he had observed 108 out of the 125 clusters in the Astroleague's Open Cluster Observing Program. Although progress was difficult due to cloudy skies during the past few weeks, he is pleased that he's close to finishing the challenge. Additionally, Russ told club members about ChatGPT, a computer program that answers users' prompts. As a testament to the power of this tool, some university faculty have typed in their final exams and recieved the answers to those exams. Russ also asked the program to write a syllabus for a college level introductory Astronomy course, and the website produced a wonderful syllabus with recommendations for textbooks. ChatGPT shows the power of AI and its potential to change the world as we know it.
Moving on, Jon Wallace had been observing the Horsehead Nebula. Thanks to a good telescope, he got great shots of the nebula despite the clouds, full moon, and street lights.
Rob recommends The End of Everything, by cosmologist Katy Mack. The book discusses the ultimate fate of the universe according to experts from a variety of fields.
Finally, Craig Snapp reminded the club that Russ will be giving a talk to the Midcoast Beacon in Feburary. He encouraged club members to check out the talk and show Russ their support.
Speaker Portion
Our speaker for the meeting was Dr. Ralph Lorenz, a planetary scientist and engineer at the Johns Hopkins University Applied Physics Laboratory. Dr. Lorenz completed his bachelor's degree and Ph.D. in the UK. He completed his post-doctoral at the University of Arizona and joined the staff at JHU APL in 2006. In the APL he's been involved in several planetary missions such as InSight PS, Akatsuki PS, and the Perseverance SuperCam Co-I. Additionally, he has co authored 10 books and over 300 publications. Most of his time is spent being the Mission Architect for Dragonfly, a rotorcraft mission to investigate Titan's surface material and determine its suitability for life. He is also the leader of the VASI (Venus Atmospheric Structure Investigation) instrument aboard NASA’s Deep Atmosphere Venus Investigation of Noble Gases, Chemistry, and Imaging, or DAVINCI mission to Venus.
Venus has been the subject of astronomical interest for over 50 years, but research into the planet has slowed over the past two decades.
Ralph began his talk by providing historical discoveries and background information on the planet. Firstly, the polarization of reflected sunlight showed that Venus' clouds could not be composed of liquid water. Analysis in the late 1960s of data from the United States and France found that Venus' clouds consisted of 75% sulfuric acid. Additionally, these clouds have high albedo (high light reflectivity) and according to infrared measurements, the cloud's top temperature is around 220-255K.
However, knowing cloud temperature doesn't tell you about surface temperature. Scientists understood that as they move down from the clouds, the air temperature gets higher, however, they did know how deep the atmosphere went. The radio telescope at Naval Research Laboratory was the first to tell researchers the surface temperature, and the instrument indicated a radio brightness temperature for Venus of 600K.
But was this the surface temperature at the bottom of a thick greenhouse atmosphere? Or was it the nonthermal synchrotron radiation? To resolve this paradox researchers sought to employ a microwave radiometer to measure whether Venus's radio brightness was the strongest in the middle of the disk or at the edge (cyclotron).
The Soviet Union was particularly interested in observing Venus as well and from the 1960s to 1972 developed Venera probes to get deep into Venus's atmosphere and measure surface temperature. They used the knowledge and failures from previous missions to improve on each additional probe, till Venera 8, which was the Soviet's first successful mission to Venus. The probe returned pressure, temperature, winds and gamma-ray measurements indicating rock composition. With this probe scientists were able to discern that the surface pressure was 90 Bar and the surface temperature was extremely high.
Moving on, Venera 9 and 10 returned the first pictures of Venus's surface and Venera 13 and 14 provided color images, wind speed from sound, and microseisms.
In the 1970s, NASA launched Pioneer Venus, a mission to assess the Venusian solar wind and map the surface of the planet. The project deployed three small probes and one large into Venus' atmosphere. They included tools for direct-to-Earth telecommunication, and the four probes helped provide a variety of input on atmosphere and climate conditions.
For the design of the instruments, NASA had a 13.5-carat diamond imported and used for the infrared radiometer. The material provided tolerance to pressure and temperature. The initial design also used a ribless guide parachute for stability. But in a high-speed test, the parachute shredded, so it was switched to a stronger conical ribbon parachute. Additionally, NASA originally intended that the parachute would be retained down to 40km, but a combination of heat and sulfuric acid destroyed the fabric and risers, so it was changed to 47km release.
Unfortunately, the external sensors on all four Pioneer Venus probes failed at around 12km altitude. This malfunction was attributed to the chemical breakdown of reinforcement at a late stage in construction. With this setback, NASA understood that careful materials selection and testing were essential in planetary missions. They used their knowledge to propel Magellan, a 'radar mapping' and highly successful mission to Venus. The spacecraft had no cameras or spectrometers, just the radar. The instrument was able to image the entire surface of Venus and got global coverage at 100m resolution.
Halfway around the world, the Japan Aerospace Exploration Agency (JAXA) set its eyes on Venus. In 2010, JAXA launched Akatsuki, a Venus weather satellite. The purpose of the mission was to understand the atmospheric dynamics and cloud physics of Venus. The satellite would move in the same motion as the cloud and by hanging in the sky, it would make 'movies' of cloud movement and turbulence in Venus.
Unfortunately, the spacecraft experienced an orbit insertion anomaly. The reason for the failure was that the fuel-side pressurization line was blocked, thus restricting helium flow. This limited fuel supply to the orbiter's main engine, while the engine ran lean and hot. The ceramic nozzle cracked causing severe torque, and thus, fault protection terminated the burn.
On the day of successful orbit insertion, JAXA got early images of Venus, which revealed cooler highlands on the planet. As to the status of Akatsuki, 13 years after its launch, the thermal IR camera and UV camera have continued operation. Data gathered from the instruments, and radio occultations have produced a steady stream of results papers. Moreover, a Lightning and Airglow Camera (LAC) continues to assess Venus, but its operation has been limited to when the planet experiences umbra. Finally, scientists have pondered whether Venus has lightning. But research leans that the planet likely doesn't experience the phenomenon.
Currently, NASA is making plans for their Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission, which will descend onto Venus's surface in mid-2031. The VASI (Venus Atmospheric Structure Investigation) instrument aboard the probe will measure wind turbulence, pressure, and temperature with high resolution. DAVINCI's high-resolution measurements and descent imaging will be similar to that of the Huygens probe and will allow similar ground-truthing of existing and future radar image data. There are Venus test chambers and simulators at the APL, NASA Goddard Space Flight Center, and the Glenn Research Center, which will allow scientists to model the conditions of Venus and improve the probes.
The final Venus mission in the works is VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy). The spacecraft will image Venus' surface and answer questions about its geology using topography, near-infrared spectroscopy, and radar image data. Although Venus is similar to Earth in size and age, the conditions of the planet are less conducive to life. Understanding the geology of Venus, will therefore provide insight on how planets that support life evolved.
Constellation Tour
To end the meeting, Russ Pinizzotto led us on a tour of the constellations Cancer, and Canis Minor. Firstly, in Cancer is Iota Cancri, a colorful double star. There are also clusters, Messier 44 and Messier 67. Finally, are the following galaxies: NGC 2775, NGC 2535, NGC 2536, and NGC 2608.
Likewise, in Canis Minor lies Procyon, the seventh brightest star in the sky, and Luyten’s Star, a red dwarf with a large proper motion. There are also 14 CMi, NGC 2485, NGC 2459, NGC 2394, Abell 24, and the quasar, QSO 70842+1835. Finally, is OJ 287; a BL Lacerte object composed of two black holes orbiting each other. One has a lot of dust, debris and a disk. The second black hole goes through the disk and emits a brief flash of light.
Russ Pinizzotto will be out of town next month, so there won’t be a constellation tour in February. However the tour will continue in March.
Summary by:
Maame Andoh