Von R. Eshleman

Key takeaways

Von R. Eshleman belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Von R. Eshleman to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Von R. Eshleman from memory before moving on to harder problems.

Reference excerpt

Von Russel Eshleman (1924–2017) was an American radio astronomer.

Biography Eshleman was born on September 17, 1924, in Covington, Ohio. His family was of Old German Baptist Brethren ancestry; he was the youngest of four sons. During the war, Eshleman served in the US Navy as an electronics technician (1943–1946). While in the Navy, he became interested in astronomy, thinking about "bouncing radio signals from the lunar surface". He unsuccessfully tried to do it using the ship's radar. After the war, Eshleman studied at the General Motors Institute of Technology, Ohio State University and the George Washington University. He received his BSc in electrical engineering from the latter in 1949. He get his MSc (1950) and PhD (1952) from Stanford University. His thesis was on "radio reflections from ionized meteor trails in the upper Earth's atmosphere", advised by Oswald Garrison Villard Jr. and Laurence Albert Manning. Eshleman was supported by both Office of Naval Research and Air Force. The Air Force was mainly interested in Eshleman's idea to use meteor ionization trails as a secure communication channel. He then became a researcher at Stanford, promoted to assistant professor in 1957 and to full professor in 1962. In the same year, he cofounded the Stanford Center for Radar Astronomy which performed radio science experiments with Pioneer 6, 7, 8, and 9 spacecraft. In 1959, Eshleman "recorded the first distinguishable echo of a radar signal bounced off the sun". He then switched to planetary exploration using radio science experiments. Eshleman became the PI of Radio Science Experiment for the twin Voyager program spacecraft, sent to the outer solar system. After Voyager, Eshleman worked on "evolute flashes during deep radio occultations, stellar gravitational lenses and their effects on propagating radio waves, ring particle dynamics, absorption in planetary atmospheres ... and retro-reflection from icy planetary surfaces." In 1979, Eshleman became the first who propose to use the Sun as a gravitational lens. Eshleman authored more than a hundred articles.

Awards and recognition Member of the Academy of Engineering Fellow of the IEEE Fellow of the American Astronomical Society NASA Exceptional Scientific Achievement Medal (1981)

Personal life Eshleman met his future wife, Patricia Middleton, in Stanford. They married in 1947 and had four children. Eshleman retired in 1992. He died on September 22, 2017, in Palo Alto, California, at 93.

Selected publications Kliore, Arvydas; Cain, Dan L.; Levy, Gerald S.; Eshleman, Von R.; Fjeldbo, Gunnar; Drake, Frank D. (10 September 1965). "Occultation Experiment: Results of the First Direct Measurement of Mars's Atmosphere and Ionosphere". Science. 149 (3689): 1243–1248. Bibcode:1965Sci...149.1243K. doi:10.1126/science.149.3689.1243. PMID 17747455. Fjeldbo, Gunnar; Fjeldbo, Wencke C.; Eshleman, Von R. (1966). "Models for the atmosphere of Mars based on the Mariner 4 Occultation Experiment". Journal of Geophysical Research. 71 (9): 2307–2316. Bibcode:1966JGR....71.2307F. doi:10.1029/JZ071i009p02307. ISSN 2156-2202. Fjeldbo, Gunnar; Eshleman, Von R. (1 August 1968). "The atmosphere of mars analyzed by integral inversion of the Mariner IV occultation data". Planetary and Space Science. 16 (8): 1035–1059. Bibcode:1968P&SS...16.1035F. doi:10.1016/0032-0633(68)90020-2. ISSN 0032-0633. Fjeldbo, G.; Kliore, A. J.; Eshleman, V. R. (1971). "The Neutral Atmosphere of Venus as Studied with the Mariner V Radio Occultation Experiments". Astronomical Journal. 76: 123. Bibcode:1971AJ.....76..123F. doi:10.1086/111096. Eshleman, Von R. (1 September 1973). "The radio occultation method for the study of planetary atmospheres". Planetary and Space Science. 21 (9): 1521–1531. Bibcode:1973P&SS...21.1521E. doi:10.1016/0032-0633(73)90059-7. ISSN 0032-0633. Eshleman, Von R. (14 September 1979). "Gravitational Lens of the Sun: Its Potential for Observations and Communications over Interstellar Distances". Science. 205 (4411): 1133–1135. Bibcode:1979Sci...205.1133E. doi:10.1126/science.205.4411.1133. PMID 17735051. Marouf, Essam A.; Leonard Tyler, G.; Zebker, Howard A.; Simpson, Richard A.; Eshleman, Von R. (1 May 1983). "Particle size distributions in Saturn's rings from voyager 1 radio occultation". Icarus. 54 (2): 189–211. Bibcode:1983Icar...54..189M. doi:10.1016/0019-1035(83)90192-6. ISSN 0019-1035. Tyler, G. Leonard; Marouf, Essam A.; Simpson, Richard A.; Zebker, Howard A.; Eshleman, Von R. (1 May 1983). "The microwave opacity of Saturn's rings at wavelengths of 3.6 and 13 cm from Voyager 1 radio occultation". Icarus. 54 (2): 160–188. Bibcode:1983Icar...54..160T. doi:10.1016/0019-1035(83)90191-4. ISSN 0019-1035.

References

Illustrations

Worked examples

Example 1 — a first encounter with Von R. Eshleman

Start with the simplest possible case. Write down what Von R. Eshleman claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Von R. Eshleman before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Von R. Eshleman ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Von R. Eshleman

In research: Von R. Eshleman appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Von R. Eshleman in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Von R. Eshleman is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1924 births, 2017 deaths, American astronomers, so understanding it makes those chapters shorter.
In everyday life: Look for Von R. Eshleman outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Von R. Eshleman in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Von R. Eshleman means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Von R. Eshleman out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Von R. Eshleman in simple terms?

Von Russel Eshleman (1924–2017) was an American radio astronomer. Biography Eshleman was born on September 17, 1924, in Covington, Ohio.

Why does Von R. Eshleman matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Von R. Eshleman?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Von R. Eshleman.