1360 days since start of observations
167.37 hours of lunar observations
131.75 TB of lunar images
112 NEO lunar impact events
NELIOTA impact flashes

Location of the impact flashes detected so far by NELIOTA.

Video coverage by


System Concept

The NELIOTA system consists of four main systems deployed in two remote sites, in Kryoneri and Athens. The Observation and Detection System are deployed in Kryoneri, while the Archive and Publication System are deployed in Athens.



Component Type Description
ArchOperHMI H2M Interface Archive system operator interface
ArchPublIF M2M Interface The interface between the archive and the publication
ArchSys Top-level component Events archiving and expert validation
ArcIF M2M Interface The interface of the Krioneri-to-Athens events transfer
ARCSTO Sub-System A database-driven storage array for the NELIOTA archive
ArcStoIF M2M Interface The archive storage interface
CAM Sub-System A fast-frame double camera system
CamIF M2M Interface The camera interface
DetOperHMI H2M Interface Operator interface for events processing
DetSys Top-level component Events detection
ExpOperHMI H2M Interface NELIOTA expert operator interface
GPS Sub-System A GPS-based time server
GpsIF M2M Interface The GPS interface
MET Sub-System A meteorological station
MetIF M2M Interface The meteorological station interface
ObsOperHMI H2M Interface Operator interface for observation (camera, frames) control
ObsSys Top-level component Observations and recording
ODSTO Sub-System A high-performance storage
OdStoIF M2M Interface The high-performance storage interface
PublOperHMI H2M Interface NELIOTA publication services operator interface
PublSys Top-Level component Events publication and information services
TEL Sub-System 1.2m Kryoneri telescope
TelIF M2M Interface The telescope interface
WebUserHMI H2M Interface Web-based interface for all the external users                                


Operator/User Component Description
AnonUser PublSys Anonymous user of restricted archive services
ArchOper ArchSys The archiving domain operator
DetOper DetSys The detection domain operator
ExpOper ArchSys The NEO impact events expert
ObsOper ObsSys The observation domain operator
PublOper PublSys The information domain operator
RegUser PublSys Registered user of extended archive services




The IT hardware of the NELIOTA system satisfies the requirements of the NELIOTA operation, namely a) high-performance storage resources, in order to support the high data rate, b) high-protection storage virtualization, to ensure integrity for saving the data and c) high-performance processing resources, in order to perform the processing of large volumes of data in a reasonable amount of time.


The Cluster System consists of

  1. Two (2) nodes HP DL380 Gen9 Servers.
  2. A storage Subsystem of an HP MSA 2040 SAN DC SFF Storage with an additional HP D2700 Disk Enclosure. The Storage Subsystem is populated with 32xHP 1.2TB 6GB SAS 10K SFF DP ENT HDDs, providing total RAW capacity 38.4TB.
  3. Network has been implemented in 2-ring concept. Inner (Red) Ring Network: iSCSI network. Very high speed dedicated network for data transfer between servers and MSA Storage Array. Private isolated and secured network. Outer (blue) Ring Network: Typical communication network for device management, routing configurations and remote access to devices for healthy operation monitoring.

The conceptual physical architecture of the system is presented in the following figures:


GPS-based Network Time Server

A local GPS-based NTP server is used as a time reference for all NELIOTA systems. It is characterized as a stratum 1 time server for the local network nodes (the latter could serve as stratum 2), while the remote NTP systems are in the best case stratum 2 time servers. The time server and GPS antenna have been installed at the Kryoneri telescope.


The general architecture of the NTP server is depicted below.


Meinberg Lantime M200 GPS Receiver and NTP Server


High performance GPS antenna