mesosphere

Mesosphere refers to two related but distinct concepts in science and technology. In atmospheric science, the mesosphere is the third layer of Earth's atmosphere, lying above the stratosphere and below the thermosphere. It extends roughly from 50 to 85 kilometers above the surface. In this region, air density is extremely low and temperature generally decreases with altitude, making the mesosphere the coldest part of the atmosphere, with temperatures around -90°C to -100°C near the upper boundary. The mesosphere is the scene of meteoroid ablation as they encounter increasing atmospheric drag, and it hosts noctilucent clouds at high latitudes in summer. The upper boundary is known as the mesopause, which marks the transition to the thermosphere.

In planetary science, the term mesosphere is used for similar middle atmospheric layers on other planets and moons, defined by its position between lower, stratosphere-like layers and upper, thermosphere-like layers. The exact temperature, density, and composition of a planetary mesosphere vary widely between worlds.

In technology, Mesosphere refers to a software company that developed Apache Mesos, an open-source cluster manager designed to abstract CPU, memory, storage, and other resources to enable efficient resource sharing in data centers. The company built DC/OS (Datacenter Operating System) on top of Mesos to orchestrate containerized workloads and data-processing frameworks. In 2019, the company rebranded as D2iQ, while Apache Mesos remains the open-source project at the core of its lineage.