physics

JEM-EUSO

JEM-EUSO is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand JEM-EUSO rather than just read about it. In short: The Extreme Universe Space Observatory onboard Japanese Experiment Module (JEM-EUSO) is the first space mission concept devoted to the investigation of cosmic rays and neutrinos of extreme energy (E > 5×1019 eV). Using the Earth's atmosphere as a giant detector, the detection is performed by looking at the streak of fluorescence produced when such a particle interacts with the Earth's atmosphere.

Key takeaways

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

Reference excerpt

The Extreme Universe Space Observatory onboard Japanese Experiment Module (JEM-EUSO) is the first space mission concept devoted to the investigation of cosmic rays and neutrinos of extreme energy (E > 5×1019 eV). Using the Earth's atmosphere as a giant detector, the detection is performed by looking at the streak of fluorescence produced when such a particle interacts with the Earth's atmosphere.

EUSO EUSO was a mission of the European Space Agency, designed to be hosted on the International Space Station as an external payload of the Columbus. EUSO successfully completed the "Phase A" study, however in 2004, ESA decided not to proceed with the mission because of programmatic and financial constraints. The mission was then re-oriented as a payload to be hosted on board the JEM module of the Japanese KIBO facility of the ISS. The mission was then renamed JEM-EUSO.

JEM-EUSO JEM-EUSO is currently (2013) studied by RIKEN and JAXA, in collaboration with 95 other institutions from 16 countries aiming for a flight after 2020. The proposed instrument consists of a set of three large Fresnel lenses of 2.65-metre diameter (with top and bottom cut off to reduce the minimum diameter to 1.9-metre so that they fit in the HTV resupply vehicle in which the instrument is to be launched) feeding a detector consisting of 137 modules each a 48 x 48 array of photomultipliers. The imaging takes place in the 300 nm-450 nm band (low-energy UV through deep-blue), and photons are time-tagged with 2.5-microsecond precision.

Orbital debris detection In addition to its main, science mission, EUSO might also be used to detect orbiting space junk that could pose a threat to ISS, that is too small to be spotted by astronomers (1 to 10 cm). The ISS is shielded adequately against particles that are smaller than 1 cm. Particles in this range, or larger, can inflict serious damage, especially to other objects in orbit, since many of them are traveling at speeds of about 36,000 km/h. Nearly 3,000 tons of space debris resides in low Earth orbit; more than 700,000 pieces of debris larger than 1 cm now orbit Earth. A laser might then be used to deflect dangerous particles. The project could be ready to implement after about 2017–2018, using better lasers.

Other projects under the EUSO framework

EUSO-TA (Extreme Universe Space Observatory-Telescope Array): a ground-based telescope designed to prove the technology of EUSO telescopes. Was installed at Black Rock Mesa, Utah, United States at one of the Telescope Array fluorescence detectors in March 2013 (first observations in 2015). The experiment was on-going in 2018. The experiment has detected some UHECR-events (Ultra High Energy Cosmic Ray). EUSO-Balloon: a balloon-based EUSO telescope meant to further validate the technology. The balloon flight took place in 2014 in Canada and lasted 5 hours. The telescope observed laser-simulated cosmic ray events. EUSO-SPB (EUSO-Super Pressure Balloon): a high-altitude heavy-lift balloon EUSO telescope. Launched in 2017 from New Zealand (EUSO-SPB1-mission). The flight took 13 days, but was cut substantially shorter than the planned 100 days. Second mission (EUSO-SPB2) is planned for 2021. TUS (Tracking Ultraviolet Setup): a Russian mission on board the Lomonosov-satellite (launched 2016); included in the EUSO program as of 2018 (originally was not part of EUSO program). Mini-EUSO: an ultraviolet telescope operated at the ISS. The telescope serves as a pathfinder mission for UCHER-missions in space and maps the ultraviolet background produced by Earth atmosphere. The mapping of the UV-background is important for the follow-up missions K-EUSO and JEM-EUSO. The mission started as a co-operation between Italian Space Agency and Russian Space Agency. The Mini-EUSO telescope was launched to ISS on 22 August 2019. K-EUSO (KLYPVE-EUSO; KLYPVE is a Russian acronym for extreme energy cosmic rays): a Russian Space Agency project to place an UHECR telescope in the Russian segment of ISS. The project builds upon the TUS-experiment of the Russian Lomonosov-satellite. In 2017, the launch was scheduled for 2022. JEM-EUSO (Japanese Experiment Module-EUSO): the final goal of the JEM-EUSO program is to have the JEM-EUSO telescope installed into ISS. POEMMA (Probe Of Multi-Messenger Astrophysics): a dedicated satellite mission (2 satellites) to observe UHECR-events in the atmosphere. As of 2018, it is a NASA-sponsored concept study.

References

External links JEM-EUSO webpage ESA EUSO webpage

Worked examples

Example 1 — a first encounter with JEM-EUSO

Start with the simplest possible case. Write down what JEM-EUSO claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, 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 JEM-EUSO 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 JEM-EUSO 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 JEM-EUSO

In research: JEM-EUSO appears in physics 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 JEM-EUSO 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: JEM-EUSO is common in secondary-school and first-year university syllabi. It links to neighbouring topics Components of the International Space Station, High energy particle telescopes, International Space Station experiments, so understanding it makes those chapters shorter.
In everyday life: Look for JEM-EUSO 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.

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How to study JEM-EUSO in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what JEM-EUSO 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 JEM-EUSO out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is JEM-EUSO in simple terms?

Why does JEM-EUSO matter?

Because it connects several physics 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 JEM-EUSO?

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 JEM-EUSO.