biology

MELOS

MELOS is a biology 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 MELOS rather than just read about it. In short: MELOS (Mars Exploration of Life and Organism Search) is a Japanese rover mission concept under study for an engineering demonstration of precision landing, and to look for possible biosignatures on Mars using a rover. JAXA has not published updates since 2015.

Key takeaways

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

Reference excerpt

MELOS (Mars Exploration of Life and Organism Search) is a Japanese rover mission concept under study for an engineering demonstration of precision landing, and to look for possible biosignatures on Mars using a rover. JAXA has not published updates since 2015.

History Japan's aerospace agency (JAXA) started to develop the mission concept on 2008, when MELOS stood for "Mars Explorations with Landers and Orbiters" or "Mars Exploration with Lander-Orbiter Synergy" which included several landers to be deployed simultaneously, that were to study meteorology and atmospheric gas escape. The first MELOS concept would have consisted of an orbiter and up to 4 small landers; all elements would be launched together on the same rocket. The orbiter would study the atmosphere, its and interactions with the solar wind, and image the current weather. Each of the four stationary landers would have been deployed on pre-determined landing sites and perform different measurements:

Orbiter — Meteorology Lander A — Surface Lander B — Astrobiology —This lander would analyze soil near a methane vent. The proposed method is to use fluorochrome dye and a microscope to stain and scan for proteins and cellular membranes. The target sensitivity would be 10 cells / 1 g of soil (compared to 104 cells / 1 g in Earth desert). It would also detect other organic biosignatures or biomolecules. Lander C — Interior Lander D — Sample return By 2015, MELOS was down-scaled to a rover mission for an engineering demonstration, and possibly an aircraft. Under the latest concept, MELOS stands for "Mars Exploration of Life and Organism Search".

Rover As of July 2015, the concept proposal includes a robotic rover whose primary objective is an engineering demonstration for long-range roving. Its secondary objective is science, specifically: meteorology, geology and astrobiology. The demonstration rover would use NASA's sky crane system for landing, and once on the surface, would deploy the MELOS rover.

Scientific objectives and payload The scientific objectives of the mission include:

Meteorology Basic meteorological observations, dust devil observation and dust entrainment. Payload: thermometer, anemometer, barometer. Optional instruments include: a spectroscope for methane detection, a dust particle sensor, electromagnetic & sonic wave measurement of dust, and short range LIDAR. Geology Geological description of the landing site including interior layered deposits and subsurface structure of regolith. Payload: ground penetrating radar (10-50m depth), multi-band stereo cameras (400-980 nm), VIS-NIR spectrometer (10ｰ20 nm). Optional: Geochronology Instrument (isochron dating method). Astrobiology Identification of biosignatures (current life from Mars or Earth). Payload: sample arm, fluorescence microscope (using pigments to visualize living cells), and an optional "daughter rover" to access samples in difficult places.

Aircraft

The mission concept also contemplates the optional deployment of a robotic airplane as a flight technology demonstrator. It would have a wing span of 1.2 m, mass of 2.1 kg and would be released at an altitude of 16,400 feet (5 km) during the entry and landing event. Its flight duration is estimated at 4 minutes, covering a distance of 25 km (16 mi). Its only scientific payload would be a camera.

Proposed landing sites The proposed landing sites will target 'wet' environments and include Valles Marineris (Melas Chasm and Juvantae Chasm), located near the confirmed recurring slope lineae, and Marte Vallis near dark slope streaks. Since the mission aims for access to a "special region", strict planetary protection sterilization protocols must be followed to prevent forward contamination of Earth microbes to Mars.

See also Astrobiology Akatsuki Life on Mars Nozomi - Mars flyby

References

Worked examples

Example 1 — a first encounter with MELOS

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

In research: MELOS appears in biology 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 MELOS 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: MELOS is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cancelled Mars rovers, Cancelled astrobiology space missions, Cancelled missions to Mars, so understanding it makes those chapters shorter.
In everyday life: Look for MELOS 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 MELOS in 20 minutes

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

Frequently asked questions

What is MELOS in simple terms?

Why does MELOS matter?

Because it connects several biology 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 MELOS?

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 MELOS.