January 05, 2026
Interplanetary Dust Particles (IDPs) are microscopic shrapnel from comets and asteroids that form our atmosphere's mysterious "meteor layer", and show up as “shooting star” in night. Dust EXperiment (DEX) is the first Indian-made instrument to hunt for such high-speed IDPs. This compact instrument is tuned to "hear" impacts, capturing vital data that redefines our understanding of the universe and charts the path for safe human deep-space missions. At the core of the experiment lies a 3-kilogram dust detector based on the cutting-edge hypervelocity principle designed to capture high-speed space dust impacts with only 4.5 W power consumption.
DEX was flown on PSLV Orbital Experimental Module (POEM) of the PSLV-C58 XPoSat mission on 1st January 2024, and rocketed to 350 km altitude (Fig.1). The 140° wide-view detector successfully logged signals of orbital debris’ (dust) impacts (Fig.2) during 01 January to 09 February 2024, confirming the instrument's capability to identify and measure such events. Skimming Earth's atmosphere on a 9.5o inclination, the detector registered several hits: a cosmic invader striking every thousand seconds.
Figure 1: Flight model of DEX on POEM of the PSLV C58 XPoSat mission
Figure 2: Typical dust impact signal provided by DEX, corresponding to orbit 207 on 14 January 2024. The unit of time on x-axis is in micro-second.
DEX delivered the most recent observations of IDPs entering Earth’s atmosphere. Definitive measurements of the dust flux of 6.5 × 10−3 [in range 3 × 10−3, 1 × 10−2 ] particles m−2 s−1 (Fig.3) is an exciting confirmation of the constant bombardment from outer space.
Figure 3: Flux derived from the DEX measurement, plotted along with Grün et al. (1985) flux model.
At present, we have no measurements of cosmic dust in the thick atmosphere of Venus or in the thin atmosphere of the red planet Mars. DEX is a blueprint of the detector which can study the cosmic dust particle at any planet having atmosphere or no atmosphere. The proven success of the Earth-orbiting DEX can provide the first-ever direct measurements of IDP within the uncharted atmospheres of Venus or Mars, but can also provide new measurements around the Moon. Beyond pure science, this data is mission-critical. The ability to measure IDPs is essential for monitoring the space environment, precisely assessing hazards for our satellites, and ultimately, ensuring the safety and success of future manned missions to Moon, Mars and beyond.
The cosmic dust detector, Dust EXperiment (DEX) has been developed by Physical Research Laboratory (PRL), Ahmedabad.
Ref: Pabari et al. (2025), DEX in near Earth orbit in light of Venus Orbiter Dust Experiment, Scientific Reports, Nature Portfolio, 15, 38168. DOI: https://doi.org/10.1038/s41598-025-21988-2